No one wants to know how clever you are. They don't want an insight into your mind, thrilling as it might be. They want an insight into their own.

As a teenager, I was always this strange mixture of kind of vice-captain of the rugby team and sensitive artist type the rest of the time. I was sent away to this public school in the middle of nowhere, and I think we managed to completely miss out on normal youth culture.

And when the universe has finished exploding all the stars will slow down, like a ball that has been thrown into the air, and they will come to a halt and they will all begin to fall towards the centre of the universe again. And then there will be nothing to stop us seeing all the stars in the world because they will all be moving towards us, gradually faster and faster, and we will know that the world is going to end soon because when we look up into the sky at night there will be no darkness, just the blazing light of billions and billions of stars, all falling.

Jane Austen was writing about boring people with desperately limited lives. We forget this because we've seen too many of her books on screen.

One person looks around and sees a universe created by a god who watches over its long unfurling, marking the fall of sparrows and listening to the prayers of his finest creation. Another person believes that life, in all its baroque complexity, is a chemical aberration that will briefly decorate the surface of a ball of rock spinning somewhere among a billion galaxies. And the two of them could talk for hours and find no great difference between one another, for neither set of beliefs make us kinder or wiser.

Things can be funny when people are uneasy. It softens them up and stops them falling asleep on the sofa. I like those moments where people half-smile and half-wince.

Being clever was when you looked at how things were and used the evidence to work out something new.