I am talking about the end of the movie. So if you haven't seen it, and don't want to know the end, run! Run away from this journal post, and possibly cover your eyes (prefrably after you are finished running)
I'm mulling over two theories. One, the charecter knows she was tricking him, but decided to love her anyway (most plausable). The second (way more of the wall/popped into my head this morning), the man with a moustache, and the one without one were two different worlds. When he shaved his moustache his world changed as much as his face.