In the school holidays, I worked at a soft drinks factory in Southport.

Cleaning the changing rooms at Kensington leisure centre from the age of 16.

When I was 15, I conned my way into an office job at a company that represented makers of breast implants. The manager had a wart on the end of her tongue that she’d push against her teeth, making a very specific sound.

Cleaning around the feet of John Malkovich with industrial carpet cleaner while he was trying to learn lines in the foyer of a theatre.

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.

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.

A road track car, a Porsche GT3. I’ve done the 24-hour race in Le Mans, which was a dream come true.

Those lactate sessions were the worst. I'd be in a lab on a turbo trainer and I'd do four 30-second efforts at 100% effort. It sounds so innocuous but the difference between 99% and 100% is huge. You can finish at 99% and you'll be hurting but if you push a tiny bit more – and that's the bit that makes the difference to your training – your legs just grind to a halt. It's like your engine is seizing up. My coach would unclip my feet and pull my leg over the saddle so I could just slide off onto a mat and curl up in a ball.

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?

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.