Generally, older people in their fifties, sixties, and seventies are running most countries and are CEOs of corporations. Which isn't to say there aren't entrepreneurs, but if the young were better in every respect, there'd be no reason for the old. Our life span reflects our particular life strategy.

It was like stepping on to an escalator; I could do anything. I was just made for science.

Maybe one day we will be able to take a pill that keeps us young and healthy much longer. I believe in my heart that this will happen.

Imagine that: If you could change one of the genes in an experiment, an aging gene, maybe you could slow down aging and extend lifespan.

You could have two completely different careers if you could stay healthy to 90. How fascinating that would be.

In principle, if you understood the mechanisms of keeping things repaired, you could keep things going indefinitely.

Ageing is very exciting. But if I didn't work on ageing, I'd want to work on the brain. There are really cool techniques you can use now. And bioinformatics. The methods you can use for comparing large data sets - that's so powerful.