This movie is not a social criticism, not a social realism, not a naturalism, not about family value or any moral lessons concerning raising a child or being a parent. The movie says one thing: even the biological father-son relationship is contingent and fragile. The love and bond between the father and the son cannot hold the relationship when it is impossible or too painful for them to continue the relationship. The father, mother and the son love each other, but apparently it is the best for them to go separate ways. In the end they all have their own happy life (maybe with some regrets)and their own (new) families. Father-son relation is just like relation between two lovers. If it cannot work out, it would be better just to break up and start anew. That is a very potent (unnerving for some) message of this movie. It is about modern relationship. The whole movie comes down to the surprised ending, which transforms your perspective and gives this movie a different light.