As an independent film director, I feel that often, the most interesting scenes in a movie include the unexpected moments that were never actually specifically written on the page. When an actor takes a beat or two longer to get his emotions or thoughts together while the camera is rolling, but the scene has not technically begun. Sometimes those quiet moments are the most honest and fresh. He is not "acting", he is simply "feeling" and building his emotions, and THAT to me can be magic on film.