It's the universal feeling that we all are alone - that we're all different. I think the movie's one resounding theme is that everybody feels the same, and we're all alone together. Some people come up to me on the street and thank me for helping them get through their teen years.

The wonderful thing about books is you never run out of them, you can just keep going. So I'm always finding new writers, or old writers that I just happen not to have read.

I think when people hear about a celebrity writing a book of any kind, the assumption is that it was dictated to a ghostwriter.

My dad has always just had a lot of faith in me as an artist and as a person, and he doesn't really dispense with a lot of advice when it comes to the music. He's taught me a lot over the years, but when I was taking on this project he's really hands-off about that. He just appreciates what I've done and is very supportive, and of course really proud.

Whatever it is that gives you that confidence will vary from person to person, but I do believe that it is the key to succeeding at anything in life - career, relationships, anything.

I think we do live in a very specialized society, where once you think about somebody as one thing, it's hard to change that. But I do a lot of things. I act, I write, I sing.

When you say you're 40, you can't call yourself an ingenue any more.