I feel like I'm worried about my later years in life because I feel like I'm using up so much good karma right now. There's going to be some sort of karmic backlash somewhere down the road.

I'm sure I cause just as much consternation for editors as any other actor, but it definitely makes me feel more comfortable understanding how and why all the different camera setups exist.

It's incredibly fun to play someone that you don't like. It exorcises your own demons in a way. It's cathartic. We all have things that we don't like about ourselves, little things. And I get to amplify those things and put them out there. It's fun and it has a cleansing effect.

It's just one of those things like when you're not supposed to laugh, it makes it that much harder to stop laughing. And for some reason Zach [ Galifianakis] and I get in this feedback mood of giggling, and on the set of Hangover we just couldn't get through stuff.

I was just fooling around with the piano and Todd [Phillips] was like, 'Hey there's a great spot in the movie [The Hangover] where we need a little bit of a breath in the narrative. You should write a song and stick it in there.' And I was like, 'Well, what should the song be about?' And he said, 'The tiger.' 'Oh, okay.' So I went off and I wrote this song. I came back and Todd and I tinkered with it a little more and then we shot it right then. It all happened in a day.

I didn't mention the tooth thing to anyone until it became clear that...we started to discuss just taking it out of the movie [The Hangover] because we couldn't find anything that worked and they couldn't afford to do a full like digital effect. So that's when I called my dentist and it worked out.

This may come as a surprise, given the nature of my job, but I am very guarded and contemplative. I'm not a naturally boisterous person.