For at least two thirds of the movie, if not more, you will wonder what the hell is going on. Normally at some point during most movies, you understand there is a plot and you can follow it. This one has a mystery, but not a plot. You might spend the movie trying to solve it, or if you're like me, just spend the movie very confused. But somewhere in the range of 15 to 5 minutes before the end...you'll think...oh, I get it. Oh wow, I get it.
Some one who has not seen it, asked me what the movie was about. Don't let anyone tell you what it is about. If you know what the movie is about, the movie is ruined for you (or at least the surprise ending is). This is one movie you should spend thinking, what the hell is going on? Even if it is a bit frustrating to sit through. It will move you.
Comments welcome from anyone who HAS seen it and would like to compare notes. So if you have NOT seen it, don't read the comments.