He really didn't want to do the film, thought it was going to be a dud, and could not see the director's vision for how it would really work as a film. However, once it was edited and the scenes, music, etc. all spliced up, he realized how good it was. But he filmed the whole thing thinking that it would be a dud. Crazy, because it's not like he was some inexperienced actor who hadn't been through the process before.