And then I thought that I had to be like Sherlock Holmes and I had to detach my mind at will to a remarkable degree so that I did not notice how much it was hurting inside my head.

I don't remember deciding to become a writer. You decide to become a dentist or a postman. For me, writing is like being gay. You finally admit that this is who you are, you come out and hope that no one runs away.

Siobhan also says that if you close your mouth and breathe out loudly through your nose it can mean that you are relaxed, or that you are bored, or that you are angry and it all depends on how much air comes out of your nose and how fast and what shape your mouth is when you do it and how you are sitting and what you just said before and hundreds of other things which are too complicated to work out in a few seconds.

I started writing books for children because I could illustrate them myself and because, in my innocence, I thought they'd be easier.

I am really interested in eccentric minds. It's rather like being fascinated by how cars work. It's really boring if your car works all the time. But as soon as something happens, you get the bonnet up. If someone has an abnormal or dysfunctional state of mind, you get the bonnet up.

I've written 16 children's books and five unpublished novels.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

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.