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.

We've tried to regulate things so that you at least get to go home at night and not have to pull all-nighters and see them on weekends and things. So, you know, like everything in life, it's a balance.

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.

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.

And as I was sort of doodling, I was thinking, surprise and fear - probably fairly similar so let's just lose surprise. And that left us with five.

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.

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