A good writer - and I think it's this way with actors too - even if you have two lines, you have to do the same complete work as if you're number one on the call sheet. If you get in an elevator and somebody gets on, rides two floors and gets off, that person has a reality that goes back to when they were born. They have memories, they have people, they have a life. They are doing something right now that the camera is on them in their space. We live in our own close-up all the time.