Disassociation
As he is being made to watch a film which is obviously about his parents with no other context, the protagonist is in a position of disassociation. He is simultaneously not allowed to participate in the film, but he knows something which nobody else in the theater does -- that this film is essentially about his own life. He recognizes the events on screen, but he is powerless to effect them. Identifying without control, the protagonist is placed in a disassociated state. He's witnessing his life from afar.
Hindsight
Because the film is about his parents, the protagonist possesses insight into the couple's relationship. He can recognize where they have made mistakes because he's already witnessed or experienced the results. With this peculiar hindsight, he interprets the romance of the couple -- his parents -- as reckless. He can see the flaws in their relationship, and he knows how miserable and unfortunate they will end up together, so he desires more than anything to prevent their union; however, sadly, he possesses mere hindsight and no ability to effect what he's witnessing.
Fate
Since the context for the protagonist's dream is never revealed, the reader believes for the majority of the book that the protagonist is being subjected to this bizarre film by design by some exterior party. This experience seems fated to happen to him, but the protagonist is unaware of why or by whom the film has been produced. He desires to spare his parents from their fate, but their lives have already been written and lived, despite the retroactive function of the film. In the end, the protagonist awakens in his own bed on his 21st birthday and realizes everything was a dream, but he cannot rid himself of the profound compulsion of fate which he experienced in this dream. He believes he is doomed to repeat the mistakes of his parents.
