Why does Santiago talk to himself while he's fishing?

Now that Santiago fishes alone, he notices that he often speaks aloud while he is out on the sea. It is "considered a virtue not to talk unnecessarily at sea and the old man had always considered it so and repected it...but now he said his thoughts aloud many times since there (is) no one that they could annoy". Santiago "(does) not remember when he had first started to talk aloud when he was by himself". When he had fished with the boy, the two had talked only when necessary, or at night, or "when they were storm-bound by bad weather". Santiago figures that he probably began talking aloud to himself "when the boy had left".

Santiago knows that if others could hear him talking out loud to himself they would think he is crazy, but since he knows in his own heart that he is not crazy, he does not care what others might think. And, he reasons to himself, "the rich have radios to talk to them in their boats and to bring them the baseball".