To drive an F1 car you have to be a little mad. On the morning of a race there's a mix of excitement and fear. If it's a wet track, then it's worse as you're not in control most of the time, which is the thing all drivers fear the most.

I felt confident at 24, but I am a better driver now.

When I was in Japan with my girlfriend Jessica, she would have had acupuncture every day if she could. I can just about stomach going to a chiropractor and I visited a talented one when I was there, but when he tried a needle on me, it was horrible. My muscles tightened and it didn't work at all.

I think as a 20-year-old you expect life to always be easy. You get given a good hand and the chance to race in Formula One. You think the driver can make the difference, can make up for everything else within the team. But that is not the case. You are racing in such a competitive sport so that doesn't happen.

I can't eat whatever I want, definitely not. I'm always controlled because I do a lot of fitness and triathlons, not just Formula One, so I always make sure I eat the right things.

The only time I think about life beyond F1 is when I contemplate becoming a dad. But there's no way that's going to happen while I'm still racing. To be successful in F1 you need to be very selfish in lots of ways and you're away from home for long periods. That's not the kind of father I want to be.

I need to develop a car and engineer a car in a position that feels comfortable for me, and I don't think anyone can do a better job than I can in that position. The problem for me is if I can't get the car there I do struggle more than some.