I don't want to tell a 15 or 14 year old what they should be doing. I want them to tell me. And that's what I got when I met Justin Bieber for the first time.

Anything I shouldn't laugh at makes me laugh. I mean, I'm bad at that, when somebody is singing something terribly and I'm thinking to myself, 'If I laugh now, this is the absolute worst thing I could ever do,' and then I start laughing and I can't stop.

I think if you're an unhappy person, you're always going to be an unhappy person. You're probably going to be less unhappy if your business is doing well, if I'm being honest.

I can't stand stage mothers. It doesn't work. You definitely feel that with the new generation of pop stars right now they've all managed to work it out for themselves. You have to have confidence in that. When you're young, you know your market better than I will. I love having young people on the show because I can learn from them.

I can't think of one person who is on TV who isn't vain. It's the nature of the beast. If you are on TV then you have a vanity, for sure. Just admit it! Why not?

When I think of invention, I always think of America. You're always seeing ads: 'Have you got the next big idea?' There seems to be that spirit in America of inventions and inventors.

You have to be original. The people creating a buzz on YouTube are taking risks, and they're doing something different. I like it when 15 year-olds come on and tell me what to do rather than the other way around.