You can't just tell actors, especially young ones, to 'act happy' and expect them to do it. They must in some essential way be happy.
Roger EbertWhen I write, I fall into the zone many writers, painters, musicians, athletes, and craftsmen of all sorts seem to share: In doing something I enjoy and am expert at, deliberate thought falls aside and it is all just THERE. I think of the next word no more than the composer thinks of the next note.
Roger Ebert