A pilot or a ranger in the bush.

A lawyer. I did work experience and was sent to the public gallery at the high court. The man in the dock was a 50-year-old accused of buggering a cat on the Metropolitan line. I decided to become a musician instead.

A pop star: I loved music from a very young age.

I know that for a very long time my consuming passion, which was confirmed when I contracted TB — I had TB when I was about 12 or so — was I wanted to be a physician and when I got TB I was even more determined. I want to be physician so that I can find a cure for the scourge. And, in fact, I was admitted to medical school. If we had had the funds maybe today I would have been a physician.

Max Levy, a German sprint cyclist who came second behind me a lot.

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.

Delivering papers in the freezing cold for my granny. I got paid in Panini football stickers, so it wasn’t all bad.

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?

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

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.