Living most of the time in a world created mostly in one's head, does not make for an easy passage in the real world.

Many have gone on to do important scientific work but all remember those wonderful times when we and our science were young and our excitement in meeting new challenges knew no bounds.

So that's when I saw the DNA model for the first time, in the Cavendish, and that's when I saw that this was it. And in a flash you just knew that this was very fundamental.

Innovation comes only from an assault on the unknown.

I also became interested in chemistry and gradually accumulated enough test tubes and other glassware to do chemical experiments, using small quantities of chemicals purchased from a pharmacy supply house.

I think one of the things about creativity is not to be afraid of saying the wrong thing.

In my second year, after moving to the Medical School, I began the courses of Anatomy and Physiology. I had begun to see that I was interested in cells and their functions.