A lot of the issues I faced in junior high was what got me into animation. It was easier to sit on the side and draw cartoons than to engage with people.

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.

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

Well, the film initially - we had decided to pair joy with fear because I don't know about you - for me fear was a major motivator in junior high. So we thought there's probably some good stuff there... As the film went on, we had developed all these great scenes that were really funny, but in the third act, it wasn't adding up to anything.

Every time you recall a memory, you're basically making another copy of it and at that same point it is susceptible to new changes and adaptations. So, you know, if you remember from when you were, you know, in second grade and there was Christmas and you got a present from your grandfather and your mom was wearing a red dress, that may or may not all have happened.

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.

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.