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.

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.

They're expecting us to make mistakes, and they've set up a process that allows us to correct for that and do it again and iterate. So I think that's a real key to the films that we've made.

Dr. Paul Ekman, who worked in San Francisco - still does - which is where Pixar Animation Studios is, he had early in his career identified six. That felt like a nice, manageable number of guys to design and write for. It was anger, fear, sadness, disgust, joy and surprise.

Any great movie you watch has some element of darkness or loss or some suffering in it. That's what makes the fun parts fun.

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