Anger is about fairness. If it feels that you're getting ripped off or taken advantage of, that's when anger comes up. Sadness deals with loss. And I suddenly had this new revelation - it felt like to me - that those are all true, but the real, deeper reason we have emotions is to connect us together. And that felt big to me.

Dr. Paul Ekman, who worked in San Francisco - still does - which is where Pixar Animation Studios is, he had early in his career identified six. That felt like a nice, manageable number of guys to design and write for. It was anger, fear, sadness, disgust, joy and surprise.

Well, what we do is we have a script, of course. But for us, writing is also like storyboarding. It's drawing. And so we will cut all of those drawings together with music, sound effects and dialogue. And we screen this kind of stick-figure version of the film.

You know there's always that kid in your class — and every class has one — the kid who draws all the time and is really good? That was not me. I was a lousy draftsman. But as soon as I figured out that I could make things come alive, like using the corners of my math book to make flipbooks, I was hooked.

They're expecting us to make mistakes, and they've set up a process that allows us to correct for that and do it again and iterate. So I think that's a real key to the films that we've made.

The idea kind of started with me just thinking about what would be fun to see in animation, you know - what have I not seen? For some reason, I got thinking about the human body and realizing, well, I've seen, like, traveling through the bloodstream and into the, you know, stomach and things.

People are funny -- they are able to project personality onto anything. I remember as a kid I spent a $ 5 bill once and felt so bad because the other $ 5 bill was now going to be lonely without all the other bills I had in my wallet, you just invest these dead things with life and that is our tendency as people. So animation takes advantage of that, grabs on to it, and runs with it.