I've always felt my spirit animal was a Tiger, so it's funny that now in 'Roar' with Katy Perry - which is a song we write together - there's the line: "I got the eye of the Tiger..." So I feel like there's a little bit of me in there.

Cheating is bad. That's a big mistake I've made, and I've really hurt people. I've never lied about it, though. I've always been honest.

It's nice to really have the freedom to write what I want.

I'd like to go the Cher route and act and sing and write and have a TV show and do it all.

Obviously I love writing with Katy [Pery], I feel like we're the same person when we write together. Even though we fight a lot, we fight over every line and we pull each other's hair and we cat-fight all the time, it's always worth it in the end.

I was writing songs as a kid about leprechauns and Catwoman and teapots - whatever it is that little girls wanna sing about.

I got called to write for Aerosmith, nothing ever came of it, but I ended up spending the day with Steven Tyler and going to his house and we sat down at the piano, just me and him, and he sang for me and played, then he asked me to sing for him, and then we sang harmony together. That was just a big moment where it was like 'oh my god, my life is crazy!' It was really cool.