With acting, it's all about internalizing the character for me and doing all the preparation you can. So the day you first step into your wardrobe, you can walk like the person. That's really the moment where the light bulb goes off. You're nervous; any actor will tell you that. Robert De Niro will probably tell you the same thing. He may not want to share that with you, but he probably goes through it. That's why actors are so neurotic.