What I love about the theatre is that it's always metaphorical. It's like going back to being a kid again, and we're all pretending in a room. Sometimes, when the pretending really works, I find it much, much more moving than something on film.

With English literature, if you do a bit of shonky spelling, no one dies, but if you're half-way through a maths calculation and you stick in an extra zero, everything just crashes into the ravine.

Usually people look at you when they're talking to you. I know that they're working out what I'm thinking, but I can't tell what they're thinking. It is like being in a room with a one-way mirror in a spy film.

I do not tell lies. Mother used to say that this was because I was a good person. But it is not because I am a good person. It is because I do not tell lie.

The most difficult book I wrote was the fourth in a series of linked children's books. It was like pulling teeth because the publisher wanted exactly the same but completely different. I'd much rather just do something completely different even if there's a risk of it going wrong.

I've written 16 children's books and five unpublished novels. Some of the latter were breathtakingly bad.

Siobhan said that when you are writing a book you have to include some descriptions of things. I said that I could take photographs and put them in the book. But she said the idea of a book was to describe things using words so that people could read them and make a picture in their own head.