I watched a couple of films I was in and thought, 'Those are pretty close to what we wanted them to be. I feel actually weirdly OK with it all. I can still see flaws in what I'm doing, but I think I delivered. I think I improved the film with my presence.'
The whole idea with acting is that you take some risks. And if you take some risks, you're really going to mess up sometimes. But it's not OK to mess up a movie; it's not OK to do that just so you can improve as an actor. But film-making takes a little bit of risk in every department.