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.

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.

Well, what if we did this in the mind as opposed to the brain? So instead of blood vessels and dendrites, what if it was consciousness and dream production? And that would allow us to have characters that represent emotions. And that felt like, man, that's exactly what animation does best - strong, opinionated, caricatured personalities. And that just got me excited.

The drive of the story is sort of hinted at the beginning, is Joy and Sadness and those two characters. Especially Joy starting to understand that there's more to life than being happy. And so that's based on real life observations and things that we've learned as adults.

However, for story reasons, we needed to represent them in certain ways. One of the things that sort of blew me away that I didn't know when we started is that memories are completely susceptible to change. And this is, you know, one of the many reasons why certain people are trying to get it taken out - eyewitness testimony in court cases because it's very unreliable.

Traditionally, animation has been dominated by men in the past. I don't know why it attracted guys.

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.