I agree. I don't think you have to watch it twice once you actually buy into the ending. That's where I had a hard time. DiCaprio's character had me TOTALLY believing he was a cop and that the institution made him go nuts while he was there. After the movie was over, I did some internet sleuthing and discovered that the writer did not intend for this to be and the movie indeed ended the way it was intended to. However, like FlightlessDuck, I think there are a few different plausiblet theories for the ending. That is different from The Sixth Sense in that the ending was pretty concrete for me.