What I actually wanted to do with my life is make a difference to the world. That led me into science very quickly.

I could make a difference.

To me, age doesn't make a difference in terms of how playful or fun life can be.

Little changes can start to make a difference in the world.

Oh, it makes a difference, I thought. And if it doesn't make a difference you will make it make a difference.

I believe in work. If somebody doesn't create something, however small it may be, he gets sick. An awful lot of people feel that they're treading water -- that if they vanished in smoke, it wouldn't mean anything at all in this world. And that's a despairing and destructive feeling. It'll kill you.