I knew that there was an upcoming screening where not only were we going to show it to everybody else at the studio, we also needed to move into production... And yet I was sitting there in editorial going this is not working. I'm a failure.

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.

But the truth is, at some point, our films - almost every single one of them - are really bad. And it's largely hats off to John Lasseter and Ed Catmull who have set up a system whereby they're expecting it.

The idea kind of started with me just thinking about what would be fun to see in animation, you know - what have I not seen? For some reason, I got thinking about the human body and realizing, well, I've seen, like, traveling through the bloodstream and into the, you know, stomach and things.

Parents don't want their children to lose that purity and innocence of childhood. We want to bottle that and hold onto that, but it's impossible.

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.

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.