I decided that my attention would be in the dining room. I haven’t cooked in 28 years at Chez Panisse. ... I didn’t intend to be out of the kitchen. ... Now I’m in a different world and I contribute to the collaboration of the kitchen and I’m always working with a group of colleagues who inspire me, but I really miss being actually in the solving of the performance, that effort to really come up with dishes that are delicious and right.

Of course, the most rewarding part is the "Aha" moment, the excitement of discovery and enjoyment of understanding something new, the feeling of being on top of a hill, and having a clear view. But most of the time, doing mathematics for me is like being on a long hike with no trail and no end in sight! I find discussing mathematics with colleagues of different backgrounds one of the most productive ways of making progress.

I’m a rather slow writer and I have to go to a coffee shop. I turn my back to the crowd in the cafe, so that everyone’s chatting and the noise of the place rises behind me, and then I just keep my head down and churn out my screenplay. I can’t write at home, because I get too lazy. I’ll just want to watch TV or fall asleep. But I’m not allowed to lie down and fall asleep in the cafe, right? So it kind of forces me to work.

After four knee surgeries and hundreds of shots injected into my knee weekly to alleviate swelling and pain, my body is begging me to stop the pounding. My previous three surgeries were on my right knee. My most recent knee surgery took place this July and was on my left knee.

I don't enjoy it but I know that I have got to live with [myself] if I'm not going to give it 100 per cent. The key thing is getting to the start line and knowing that I couldn't have done any more, that I didn't back off. You accept the pain, because if you didn't there would always be that element of doubt.

Jason Queally, a former teammate. He is older than me and was Olympic champion in Sydney. The way he mentored me, even though he knew I would be a rival, was amazing.

The real problem is that the pain actually gets worse. You have created massive acidosis in your muscles so there is a huge quantity of hydrogen ions and the pH in your blood changes. For 15 minutes you lie there thinking, "God, this is really bad. I'm going to die. It has never been this bad before." And every time you think exactly the same thing. You have to lie to yourself by saying you're not doing a second set. Then, without moving for 15 minutes, almost to the second, I would roll over and think, "OK, I think I can do a second set now." During those sessions I have never felt more alive or so close to death.

Scotland’s rugby captain. My hero Gavin Hastings was captain when he came to our school for a training session when I was 10 or 11. I met him and was blown away.

The London terror attack on 7/7 in 2005. I was in London the day before for the Olympic bid. When we won I thought, “I should stay over – it will be a great party tonight.” But I decided to go back to Manchester for training. Bombs went off on what would have been my route to the station.

The six Olympic gold medals, because at school I was never great at sport. When I look back on my career I think, how on Earth did that happen?