I honestly believe that after analyzing this movie this movie has changed me as a person. It imparts a kind of open-mindedness that you rarely get to experience. By forcing you to re-analyze the plot to understand the deeper meaning, the movie forces you to use your critical thinking to overcome your built up biases.

Overcoming your biases and changing your mind about a subject is something that is rarely achieved in the real world, especially if you are over a certain age and your beliefs have solidified. So, instead of challenging your real-world beliefs the movie creates a vacuum and within that vacuum it builds up biases in your mind and creates a false belief. It is then up to you to take up the incredibly difficult challenge of breaking down those biases and revising your belief system.

I think this is a truely valuable film. Na Hong-jin is a master artist.