It's amazing that more people have climbed Mount Everest than have broken the 4-minute mile.

It is a paradox to say the human body has no 'limit.' There must be a limit to the speed at which men can run. I feel this may be around 3:30 for the mile. However, another paradox remains - if an athlete manages to run 3:30, another runner could be found to marginally improve on that time.

I trained for less than three-quarters of an hour, maybe five days a week - I didn't have time to do more. But it was all about quality, not quantity - so I didn't waste time jogging, ever.

Life was very simple. My parents had come from the North of England, which is a fairly rugged, bleak, hard-working part of England, and so there was not the expectation of luxury.

It's a question of spreading the available energy, aerobic and anaerobic, evenly over four minutes. If you run one part too fast, you pay a price. If you run another part more slowly your overall time is slower.

I think that is a universal adolescent feeling, trying to find your place. The adolescent who is perfectly adjusted to his environment, I've yet to meet.

I wanted to be a neurologist. That seemed to be the most difficult, most intriguing, and the most important aspect of medicine, which had links with psychology, aggression, behavior, and human affairs.