I am not this big celebrity, but it gets really crazy. You have to go through the nuts of blowing up, in a sense, and then figuring out how to live your life with that.
I look for material that both interest me and challenges me. If I am drawn to the material and I have to work hard at it, the characters and the plots reflect the hours and hours of research.
I personally believe the film turns out better when shot in one short schedule, plus it doesn't stress the actors.