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.

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.

So this idea of moving seemed like a good way to sort of represent that metaphorically. It also is something for me personally. When I was in fifth grade - so about 11 - my folks moved us to Denmark.

We actually needed the memory - if you see the film - as a very different kind of a plot device of revealing some information to our main character. So we chose to represent it as these sort of beautiful little snow globes, which kind of, weirdly, that's the way we think of memories - at least, most of the folks that we talked to. You think of these memories as being very pure and absolute and unchanging. That's not actually real life.

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.

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.

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.