And in part that's good but then, like any emotion - and this is something we learned from the research as well - there are positive and negative aspects to all of these.

When I was in middle school, I liked to make cartoons.

But the truth is, at some point, our films - almost every single one of them - are really bad. And it's largely hats off to John Lasseter and Ed Catmull who have set up a system whereby they're expecting it.

I'm not actually sure if guilt is an emotion. In fact, that was - at the very beginning of this process, we realized, man, we really don't know very much about this subject so we better do some research. And we started looking around online.

It's like you run into this dark tunnel, trusting that somewhere there's another end to it where you're going to come out. And there's a point in the middle where it's just dark. There's no light from where you came in and there's no light at the other end; all you can do is keep running. And then you start to see a little light, and a little more light, and then, bam! You're out in the sun.

And it sort of hit me that the very subject matter of the film that I'm dealing with is the key to the most important thing in our lives, and that's our relationships. And so we had done all this research showing the job of each individual emotion, you know, fear keeps you safe. It deals with uncertainty.

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.