I feel that if I had not had an art program in my school, I would have failed in a big way. My teachers knew I was intelligent, but they didn't quite know how I was ever going to apply that intelligence. The one or two teachers who knew me well knew that it would be through drawing or acting or whatever means of expression I was allowed.

By the time that book So You Want to Be President? came along, we had already had enough presidents that had shown us that presidents are human beings. So I felt I was contributing to the common knowledge there, but not revealing anything really new - sort of supporting what everybody already was suspicious of.

My interest really is psychology, what's going on in people's minds as revealed on their faces and in their posture. That is my strength. And it's something that came from probably being a silent observer for most of my life and having to read what was going on in people's minds from only their postures or from their expressions.

I open journal, I look at the picture and I remember where I was. And I remember the time of day, the temperature of the air, what music was playing, or who was talking to me, or who was looking over my shoulder and what conversations we had and the smells of the earth and the time of year it was. It's all there for me in a way that we don't get looking at a snapshot. Most of us look back at a snapshot from ten years ago and say, where was that? We don't even remember where we were.

What I try to do in my picture books is to be all-inclusive, but not exclusive, to not exclude the kid and not exclude the parents from the experience. And it's not a very easy task; you can't find stories that work that way too much of the time.

The whole basis of working in black and white and grays became the basis of my understanding of color, because it's all about tone, it's all about light and dark. If you don't get that, then your color work is going to be a mess. So that's the beginning of the toolkit: drawing and black and white media.

I began drawing probably when I was - around the same time everybody else puts a mark on a piece of paper with a crayon - when I was two, probably. The difference between me and everybody else is, I kept doing it for the rest of my life; there was something very satisfying about that.