The original question had to be edited down. I think that one of the primary significances behind why the man and the boy struggle to be alive is that life is seen as a testament to the other. The man struggles to stay alive because of the love he has for his son. He understands that to stay alive for the welfare of his child represents a love for his son. If he were to lose the will to live and give up the struggle to stay alive, his son is endangered. Thus, the struggle to survive is an expression of love for his son. As the son becomes older, I think that his will to live is to embody and represent the lessons that have been taught to him. The son's struggle to live and survive represents how much his father has taught him and how much his father means to him. In continuing this struggle, the son understands that he honors his father and carries love for him. In the same way, to sacrifice the struggle for life helps to create a condition in which the love between both is abdicated. It is in this where I think that the son understands that the need to stay alive represents something more than simply individualistic survival. It recognizes a bond that exists between two people. In this, the struggle to stay alive is significant.