One of the pleasures of being an actor is quite simply taking a walk in someone else's shoes. And when I look at the roles I've played, I'm kind of amazed at all the wonderful adventures I've had and the different things I've learned.
If you know what it is before you even start, it's not as interesting. Central to being an actor is pretending, and the adventure of it all. That's why you become a junkie for different kinds of situations. I try to attach myself to people who really inspire me, and directors who are really passionate. That way, I can give myself more fully and trust the impulse behind why the film is being made, and I can be a little more irresponsible in finding out what the character is. I have to worry less about what the character means if I trust the director.
Central to being an actor is pretending, and the adventure of it all. That's why you become a junkie for different kinds of situations.