Bore children, and they stop reading. There's no room for self-indulgence or showing off or setting the scene.

But in life you have to take lots of decisions and if you don't take decisions you would never do anything because you would spend all your time choosing between things you could do. So it is good to have a reason why you hate some things and you like others.

...and I went into the garden and lay down and looked at the stars in the sky and made myself negligible.

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.

Most adults, unlike most children, understand the difference between a book that will hold them spellbound for a rainy Sunday afternoon and a book that will put them in touch with a part of themselves they didn't even know existed.

Prime numbers are what is left when you have taken all the patterns away. I think prime numbers are like life. They are very logical but you could never work out the rules, even if you spent all your time thinking about them.

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.