Santiago and the boy live in a world of great poverty, but support each other through participation in shared fantasy.
Take, for example, their daily ritual of asking about dinner and the cast net:
What do you have to eat?” the boy asked.
“A pot of yellow rice with fish. Do you want some?”
“No. I will eat at home. Do you want me to make the fire?”
“No. I will make it later on. Or I may eat the rice cold.”
“May I take the cast net?”
There was no cast net and the boy remembered when they had sold it. But they went through this fiction every day. There was no pot of yellow rice and fish and the boy knew this too.
It’s not that they are delusional, but that by referring to things they used to have, like the cast net, or the yellow rice with fish, they tacitly acknowledge to each other their poverty and express both their love for each other and the hope that things will get better.
“The Great DiMaggio” is possibly the best example of this sort of hope. DiMaggio represents a kind of moral and practical perfection. DiMaggio is the standard the old man strives to reach; he hopes to “be worthy” of DiMaggio, who “does all things perfectly” despite the pain of a bone spur, an injury the old man does not understand. DiMaggio becomes a kind of alter ego for the old man; he is constantly comparing his ordeal with the fish to DiMaggio’s athletic performance. He wonders if DiMaggio would have stayed as long with a fish as he has, or if he would have liked the way he hit the fish “in the brain.”
Of course, DiMaggio’s presence in his life is as much a fiction as the missing cast net. What he knows about the real DiMaggio is limited to what he can read in newspapers, but the reality of DiMaggio’s talent and fortitude is less important than the example he sets. In fact, Santiago endures far more than DiMaggio ever did, bone spurs notwithstanding. It is almost comic the disparity between Santiago’s lived experience and that of his hero, which nonetheless motivates him to hang on.
Joe Dimaggio represents excellence in performance, with the longest hitting streak in baseball history. He does not need for his team, the Yankees, to win, because winning is, in some ways, incidental to the individual's performance. Even if you may lose (the fisherman does lose the fish, and the fish loses its life) but each of them performs with courage, which Hemingway defines as "grace under pressure." You may win, you may lose, but you can ALWAYS define yourself by courage. Hemingway was much more interested in knowing how to live with honor than in trying to figure out what it all meant.