The one thing you have to do if you write a book is put yourself in someone else's shoes. The reader's shoes. You've got to entertain them.

There's something rather wonderful about the fact that Oxford is a very small city that contains most of the cultural and metropolitan facilities you could want, in terms of bookshops, theatre, cinema, conversation. But it's near enough to London to get here in an hour, and it's near enough to huge open spaces without which I would go insane.

And when you look at the sky you know you are looking at stars which are hundreds and thousands of light-years away from you. And some of the stars don’t even exist anymore because their light has taken so long to get to us that they are already dead, or they have exploded and collapsed into red dwarfs. And that makes you seem very small, and if you have difficult things in you life it is nice to think that they are what is called negligible, which means they are so small you don’t have to take them into account when you are calculating something.

At teenage parties he was always wandering into the garden, sitting on a bench in the dark . . . staring up at the constellations and pondering all those big questions about the existence of God and the nature of evil and the mystery of death, questions which seemed more important than anything else in the would until a few years passed and some real questions had been dumped into your lap, like how to earn a living, and why people fell in and out of love, and how long you could carry on smoking and then give up without getting lung cancer.

Books are like people. Some look deceptively attractive from a distance, some deceptively unappealing; some are easy company, some demand hard work that isn’t guaranteed to pay off. Some become friends and say friends for life. Some change in our absence - or perhaps it is we who change in theirs - and we meet up again only to find that we don’t get along any more.

When I was writing for children, I was writing genre fiction. It was like making a good chair. However beautiful it looked, it needed four legs of the same length, it had to be the right height and it had to be comfortable.

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.