Theater roles are written by the great masters. The greatest literature that you can possibly know are the theater roles like King Lear, Hamlet, and all of those great roles. So all you do is you dive into these unchallenged roles and see how far you can get, what kind of accolades you can get, and how good you can be in them. In movie roles, you can actually improve them by knowing a lot about your own stage technique, which helps a great deal in the cinema and how you can project inner humor even though the particular dialogue is not necessarily funny, but you can infuse it with humor.