Ignore all the negative reviews or ppl saying they couldn't follow it. If you have any common sense at all and you don't get up to go to the bathroom or what not and you are following the film closely you will understand the concepts. I was glued to the movie the whole entire time. The ending is remarkable and I left the theater deep in thought. If you are into movies that mess with your mind and make you think then this one is for you. I'm still thinking about it right now actually. I wonder how close to reality these concepts can be.