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 we can sit with Lee Unkrich and Andrew Stanton, and all the other folks and experience what the film is going to be like. And then we go away into a room, and we talk about what worked and what didn't. And then we take all of those findings and we do that whole process again.

If you were feeling sad right now and you recall a sad - or, a very happy memory from the past, it will be tinged with more sadness based on your current feeling. So we felt like that was actually on solid scientific ground .

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.

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.

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.