And it's about a three-month process every screening. And that way we have seven or eight chances at the film before we have to actually build the models, build the sets, do the animation and all of that. So it's a - I think that's a real key to the way we make films.

It's, like, you know, if you're sad, it's a way of connecting with other people. And we - a lot of times we sort of feel embarrassed by being sad, and we go off by ourselves to hide and cry by ourselves. But, really, it's a way of re-establishing relationship.

One of the other experts we consulted with, this guy named Dacher Keltner, he was big on sadness as community bonding - I think is the word he used.

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.

It is one of those weird social things. Even as parents we say, oh, don't be sad. You know, come here, we'll distract you with some ice cream or something. And I don't know if that's always the best thing. But it's certainly - you understand why people do it.

Toy Story we found, sorta by accident, because we didnt know what we were doing, the idea of being replaced by somebody. Everybody has that fear, or encounters this jealousy at some point.

And usually I'm not watching the screen. I'm kind of sitting and looking off to the side, spying on people to see what they react to' cause it's - as Joe Ranft used to say, you know, animation is like telling a joke and waiting for three years to see if anyone laughs