The 37-year-old Fighter star is often compared to Robert De Niro and Daniel Day-Lewis, but said that his acting is usually the result of 'winging it'.
He told The Mirror, 'I'm not having therapy. It's very limiting if I have to relate every damn thing in somebody else's life to something that's happened in mine. At the end of the day, I'm faking it. Pure imagination.
'I never took any classes, I just go 'I better wing this one and make it up!' Everybody talks about the process too much. The interesting thing about a movie is the movie.'
He added, 'The more I talk about it, the more I'm telling people how to react. I want to talk, but I try not to show too much of myself.'