The biggest thing that comes out of improv that gets built on is just character traits. You know, for me the singing was born out of improv.

I grew up in Georgia and I think if you're raised in the South it's where a lot of the war was fought, and it's just more present in the sort of psyche of the South. So I've always just been interested and sort of fascinated by [Civil War].

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.

I mean the fun part about when Andy Bernard sings on The Office is he usually embellishes the songs in fun, stupid ways. That's just something that I do in life, like in the shower or whatever. So a lot of that stuff is pretty spontaneous.

I'm sort of laughing and so Zach [ Galifianakis] started laughing [on the set of The Hangover]. And Todd [Phillips] was baffled because what we were saying wasn't that funny, you know what I mean? And it was like all the baby's face. So Todd was like, 'What is going on? Get it together guys.'

We spent six weeks there [in Vegas]. The only thing crazy that I did was shoot that movie [The Hangovers]. The stuff in that movie is way crazier than anything I might have done, drunk one night in Vegas. I mean we did it for real in the movie, so that's as crazy as it got.

We did some camera tests blacking it out, we made a prosthetic with a gap in it, but that made me look like a donkey, so I vetoed that right away. And then I just finally called my dentist and said, 'You know, I've had this implant for 20 years. What's it involve in taking it out?' And he said, 'It's actually not that big a deal. We can do that.' So we took it out and I was toothless for three months, for the run of the movie [ The Hangover] .I take my job very seriously.