At Monza we reach a speed of around 220mph at the end of the main straight and we don't hit the brakes until there are 150 metres to the corner, yet we can still scrub off enough of that momentum to get round the corner, lap after lap. If you want an example of just how powerful the brakes are on a Formula One car, there you have it.

By the time you do finally go for the brakes, the car has already stopped accelerating, because Monza is the one place where our cars reach maximum speed and those 150 metres disappear very quickly. It is like starting up the motorway slip road at more than three times the speed limit, braking halfway along and still expecting to get round the roundabout at the end.

At 220mph, you are pressed tight against the seatbelt straps thanks to pure speed. You are being pushed back in your seat, foot flat on the gas, waiting, waiting and then - bang-150 metres before the corner, you have to stamp on the brake so hard that you end the race with a dead foot. As your speed falls away, you are thrown forward, tensing yourself once more against the straps as, all the while, you are thrown around by the bumps. The car might look big and strong on the television screen, but remember that the whole machine only weighs 600 kilos, which is less than the weight of a rugby scrum. When you think that a good deal of that weight is taken up by a big engine and racing tyres, it's not surprising that the car goes so quickly.

Late braking is one of the arts of Formula One, a discipline that takes time to come to terms with. Plenty get it wrong, but when the car is right, it can be one of the most exciting parts of driving.

If a Formula One driver worried all the time about danger, he would be doing the wrong job. Invariably the enjoyment of racing far outweighs any trepidation. Fear is shoved aside as a totally redundant state of mind and from there you largely forget about it.

It would do you no good to occupy your thoughts with concerns about your speed or your chances of being injured. In fact, those sorts of worries would put you in more danger, because your concentration would be affected and you would be more susceptible to making errors. Drivers find it harder to go slowly than to push themselves to the extreme. If they try to stay within some kind of safe limit, they tend to seize up and lose their natural style, which is when mistakes creep in. The irony is that a frightened, nervous driver trying to stay out of trouble would probably be the most dangerous guy on the track.

A driver has to have faith in the equipment and in himself. You couldn't race if you didn't have that basic level of confidence and self-belief, that certain knowledge that, whatever gets thrown in your direction on the track, you will be able to cope. As a driver, you have to believe that you are in control of the experience and that what happens is down to you. As long as you continue to believe in yourself, you are well equipped for Formula One.

Our quest does not stem from some macho need to show off. The goal in our sport is simply to beat the other guys on the track in a straight race run according to rules that we all know and, as such, I don't hold with the description of racing drivers as being brave. I would define bravery as doing something unselfish or risking your life for the benefit of others, whereas motor racing has a far more selfish streak running through it. It's a personal challenge, a thrill and a discipline, a useful skill to learn, but is it brave? I don't think so.

The nearest we come to bravery are those occasions when a driver has to confront trepidation to get the most from his car. At somewhere like Eau Rouge, the soaring curve at the end of Spa's main straight, it can take a bit of convincing from the cockpit that you really can go flat out, but it is that sort of challenge that keeps you motivated, because we all develop a desire to push ourselves to the limit and to prove the doubter wrong. If people say Eau Rouge can't be done flat, then you can bet that every driver will give it a go at some point over the weekend, just to see if he can prove otherwise. The anxiety that haunts a driver does not come from fear of injury, but from a fear of falling short, of failing.

If I make any sort of mistake, I consider it to be costly to my performance. Losing control of my car during a Grand Prix will cost me a place or perhaps even the race itself, and the same principle is true in qualifying. I worry about crashing, but only for that reason. A crash means a bad place on the grid or no points from a race weekend, and that is a failure. Above all else, I try to drive the car as hard as I can, but you always need to deliver it back to the garage, ready to fight another day.

Mind you, we are lucky to be driving in an era when safety has become one of the sport's most pressing concerns.

Over the summer, during a break from Formula One, I drove a couple of vintage cars at Goodwood and it was quite an eye-opening experience. The whole event was meticulously planned to recreate the feel of the 1950s and 1960s, and there were few concessions to modern safety standards. Better seatbelts had been fitted or, in the case of some of the cars, belts were fitted for the first time, and the drivers were allowed to use full-face crash helmets, but otherwise the cars were unchanged from the standards of the day, an era when drivers had a much shorter life expectancy behind the wheel.

They might not have had the performance of today's Formula One cars, but to have sat in those machines and raced round the old Nurburgring, a circuit going on for nearly 14 miles without run-off areas, crash barriers or even the painted white line at the edge of the track, would have meant closing your mind to dangers that anybody could see. In those days, drivers were killed on a regular basis, but the sport went on, slowly learning its lessons.

I grew up in the full knowledge that my father raced with guys who, from time to time, were killed, so occasional deaths were part of the sport that I knew. For the past decade and a half, though, Formula One has been comparatively safe and a lot of people gradually forgot the danger that is implicit in motor racing, which is why the deaths of Ayrton Senna and Roland Ratzenberger at the San Marino Grand Prix in 1994 came as such a profound shock to so many people. Somebody like Rubens Barrichello, for instance, had been a small boy the last time a driver had been killed in a Grand Prix, and then, suddenly, two men died in a weekend.

As Ayrton's team-mate, the accident obviously had potentially serious ramifications for me. We had been using identical equipment, but it never crossed my mind not to rejoin the race that afternoon. I had to go back on to the track for the same reasons that we had all decided to race on after Roland's accident. There was no decision to be made.

I had to trust what I was being told by my engineers and I took part in that race as an act of faith in their judgment. Without that bond, how could the sport ever go on? There are times when you get out of the car and thank God that you got out of a race in one piece, and Imola was one of them, but we are racing drivers and that is our job.

We all chose to do this in the first place and, whatever happens, you carry on and take your chance. Not to have gone back into that race because my team-mate had had such a dreadful accident would have been an act of hypocrisy on my part. You cannot take up a lifestyle such as this because of all the good things and then call an abrupt halt when something bad happens - even something as bad as that.

I remember Niki Lauda's comment about the Imola weekend because it was typically astute. He said God had had his hand over Formula One, but for that weekend he had decided to lift it off. Lauda was right - we had been lucky not to have had a fatality for twelve years and we have been lucky not to have had one since, but we would be wise to remember that one day it will happen again.

Still, there are a few drivers out there who have a poor understanding of the risks, and, in a way, perhaps it helps them. The ideal attitude for a racing driver is probably to believe that he will never be hurt, which is a necessary state of mind for men and women who have done dangerous jobs throughout history. Taking risks, though, is easy if you're not fully aware of the level of danger - if a cat knew how painful it would be to fall off a roof, then it might not go up there in the first place.

There are things you can do if you are ignorant of the dangers, and driving in the wet when you cannot see is, arguably, beyond risky and into the realms of plain stupidity, but someone like Ayrton was acutely aware of the dangers he faced, which made his performances all the more remarkable. Despite any reservations he may have had, he never let fear restrict his performance. As human beings, we admire people who know the depth of the risks they are taking, rather than those who are blissfully ignorant.

A lot of drivers remain complacent about danger, while just about all of us have a fatalistic view of accidents. If it's going to happen, then it will, and there is not a lot you can do about it - like fighter pilots, racing drivers are not normally the sort of people who want to go through life cocooned in cotton wool.

Jacques Villeneuve suggested that drivers are losing the admiration of the public because Formula One is becoming too safe, but surely people won't have respect for people who take absurd risks. I calculate the odds and I accept them, but I don't see any need to load them up against me. Statistics can tell you the chances of contracting a fatal disease, or getting hit by a car, or being struck by a meteorite or swept away by a tidal wave. If you took all of them into account, you would never leave your house. There is a risk to everything, and that includes motor racing, but the positives far outweigh the negatives. As long as motor racing offers me a level of challenge and enjoyment and a way of fulfilling my potential, then the deal is a good one.

Mind you, sometimes the risks come from unexpected sources. I had two near-misses within the space of five days in September. The first one came when I was flying home from the Nurburgring, after a rather disappointing time in the Luxembourg Grand Prix - a classic case of 'just when you thought it was safe to relax'.

I was in my jet with some friends and we took off from Cologne Airport as normal. As we were climbing, I heard the undercarriage being retracted and then dropped again. Shortly afterwards, I heard the wheels being brought up once more. I made some joke about the pilots mucking about, and went back to talking about something else and looked forward to getting home.

An hour later we were approaching Farnborough, and the cloud cover was only about 1,000 feet. We banked, then jinxed back to the right and, out of nowhere, we nearly hit a hot-air balloon! Obviously the cloud had totally obscured it and, as we roared past, you could almost see the faces of the people standing in the basket of the balloon, staring at the plane and wondering what was going on. We were thinking much the same.

That wasn't the end of it. Instead of coming into land on the runway, we flew past at a height of about 500 feet, and I started to get a little bit concerned. Pete Boutwood, an old friend of mine who was flying home with us, had a word with the pilots and came back saying that there was indeed a problem with the plane. Remembering the difficulty we had had on the way out of Cologne, I was going to ask if it was to do with the undercarriage, but the answer presented itself almost immediately. As we were taking in Pete's words, one of the pilots came down to check that we all knew what to do in the event of a crash landing.

By then, everybody was paying attention. He told us there was a problem with the lights on the dashboard, which meant that he was not sure if the wheels were down or not. We had flown over the runway so that the control tower could take a look at our plane and tell us whether it looked as if the undercarriage was in place.

They had reported back that all looked well, but from that distance they were not completely sure. Without a proper reading from the instrument panel, the pilot couldn't be certain that our wheels had locked in place and were not going to buckle under the weight of the plane landing.

The problematic wheel was the one on the right-the others we were sure were okay - so the pilot brought us down gingerly on the left wheel first. Then he let the other side of the plane come down very gently, checking that the right wheel would hold firm. Mercifully, it did, and we got down in one piece.

It was an uncomfortable feeling, and as we performed our high-speed 'wheelie' along the runway, we could see the flashing lights of the fire engines and ambulances that were waiting for us, prepared to dive in to make the rescue. In those circumstances, drivers are expected to feel less scared than most people, but this was a situation that was totally out of my control, and that I don't like. Also, I'm pretty certain that my racing car would stand up to a hefty crash, but I wasn't nearly as sure about my plane.

Once we had managed to get ourselves on to firm land, and were guzzling down the obligatory sweet tea for the occasion, I had to address the problem of getting back to Dublin. My plane was out of action for a while because of the repairs that needed to be made, so I was stranded.

Rescue appeared in the shape of some racehorse trainers who were flying their horse back to Ireland. They offered me a lift and so, in the company of some living horsepower, I got home. The only difference between me and the equine passenger was that, between us, the horse had had a better day at the races. She finished third compared to my lacklustre eighth place.

Less than a week later, I was testing in Barcelona. There was a long gap between the race at the Nurburgring and the Japanese Grand Prix, and all the teams wanted to try to make an extra push.

Coming to the final corner on one of those laps, everything seemed fine. I could see Giancarlo

Fisichella, in a Benetton, just ahead of me and I realised that he had slowed down. Very quickly, I realised that he had slowed to a crawl and I was on target to thump the back of his car. It could have been a very nasty accident.

Instead, I took the only option that I had and went off the track to avoid Fisichella's car. At the time, I was in fourth gear, doing about 150mph, and I knew that it would hurt when my car hit the barrier. As I went in, I tried to relax, which is my normal practice in an accident, and took my hands off the wheel, because if you are tense, you will rip your muscles and do yourself no good in the process. There's no way you can resist the force, so you are better off trying to relax and enjoy the ride, taking a few mental notes along the way.

You get used to it. It might sound bizarre, but racing drivers are accustomed to having accidents, and they often talk about them as if they were the most exciting thing of all -as long as they get out in one piece.

When you know there will be an impact, there really is not an awful lot you can do other than watch what's happening with a mixture of interest and concern. There's an element of hoping it's not going to hurt, but often there isn't time to formulate a thought like that. Instead, you normally only have time to say a few choice swearwords, which I certainly managed to do that day in Barcelona.

As a racing driver, you assume that every season you will have one big crash. You hope that it won't happen, of course, but there tends to be one each year that shakes you up a little as a reminder of the danger of our job. I had hoped to get through 1998 without having my warning, but this was it, my biggest fright of the season. As the car went into the barrier, my helmet hit the steering wheel and my whole body was shaken up.

As I was thrown forward, I heard a fantastic 'crack' originating from somewhere under my skull. For the past year, I have been troubled by pain from the vertebrae in my neck, pain that has never been properly eased by a chiropractor, but suddenly, with that crack, it instantly felt better. The rest of me was sore, my head was aching and my knees were bruised, but the two vertebrae were fine. I have had plenty of accidents that have left me feeling bad - this was the first one that actually did me some good.

Like any racing driver, I have had my fair share of shunts. I had a big crash in Formula Ford, but I blacked out and have never been able to remember a thing about it. I had a couple of pearlers on my bike as well, and I remember once landing on my head and then being thumped by the bike as it went past. Thankfully I only broke my collarbone instead of my neck.

Bikes make you particularly vulnerable, but a car is different because you are strapped inside, and when it goes out of control, it can go anywhere and do anything. A bike tends to hit the deck and go off at a tangent, but a car can go right, left, backwards, upside down, in the air. You don't know what will happen, but you're strapped inside it as an utterly helpless passenger.

After the huge crash at the first start in Belgium, Eddie Irvine said it had been terrifying 'because it just seemed to keep going on', and I know exactly how he felt. Ever since my first crash in a racing car, I have known that there is a point in any big accident when you feel like saying, 'okay, I've had enough now'. The trouble is there is always something more to come.

The worst crashes I have had are the ones where the car's suspension fails. Normally that only happens when the suspension is under maximum load, which is when the car is at its fastest speed going round the fastest corner. An accident in those circumstances will always be enough to bring up the hairs on the back of your neck and, if you're unlucky, it's going to hurt.

I had one on the exit of the tunnel in Monaco several seasons back, where the rear suspension failed and I was very lucky not to hit anything. I went down the slip road and came to a gentle stop, thanking my lucky stars. This year, in almost exactly the same place, Alexander Wurz did the same thing, but was less lucky and bounced around all over the place. He ended up piling into a barrier, with bits of bodywork going everywhere.

If I was lucky in Monaco, then I wasn't so fortunate when my suspension failed again, this time at the exit of turn two in Estoril, in testing a few years ago, resulting in the biggest accident of my life. I was doing at least 150mph when, before I could think, the car had turned around on me. Reduced to the status of an interested observer, I felt the car thump into a barrier on the left-hand side, going backwards, and then bounce across the track.

By now, there were no wheels on the car because they were all ripped off by the first impact. In effect, my car had been converted into a carbon-fibre sledge, and I piled into the barrier on the other side of the track just as hard. At that point, I rebounded into the middle of the track and came to a halt, with steam coming up from the car and me sitting in the cockpit counting my limbs.

You may not be surprised to know that after that I went home. I wasn't badly hurt, but I was bruised and shaken up a bit and a little concussed. My attitude was pretty much 'thank God we've got that out of the way', but it was not too long before I was back at the wheel.

You can have enormous shunts and walk away from them with barely a mark on your body. Then, at other times, you have what looks like a pretty minor shunt and it really hurts. The first time I drove on a circuit after winning my world championship in 1996 was when I went to Suzuka to do some tyre testing for Bridgestone. I had done about fifteen laps when I spun coming out of the hairpin, which is the slowest corner on the circuit, and slammed into a wall on the inside of the corner. It was only a first-gear corner, but the impact was enormous and I was seeing stars, almost knocked out, and barely noticed that my car was on fire. That was the end of that - I had gone all the way to Japan for the test, destroyed the car after half an hour and had to go home. As test sessions go, it was not exactly the perfect model.

Fear is an obstacle that is there to be overcome. It represents a form of tyranny, because if you are frightened, then you are inevitably limited by your fear from doing the things you want to do. There were times when racing was the easy part for me, and it was the public appearances and press conferences, the pressure of providing something for a big group of expectant people, that I didn't like.

Now those aspects of my life don't present a problem and, like a driving test or a school exam, I look back on my early career and can't believe I was ever frightened of something that I now enjoy so much. Like falling off a motorbike, any fear has to be confronted for the first time and, after that, you normally find it a great deal less intimidating. Without confronting your fears, you can miss out on an awful lot of life's experiences. In Monza, for instance, I struggled in qualifying and worried that I might not figure in the race, but thanks to some good tactics I came home in sixth place to add another point to the collection. Get yourself a bit of self-belief, and you can do anything . . .