What do you learn about the old man while he is thinking alone in his boat?

We learn that Santiago has his own value system. He muses about his identity and his masculinity: both are invariably tied to the sea and his role as a fisherman. He is frustrated with his age and failing body. He is nostalgic about his lost youth. We learn that Santiago longs for a chance at redemption: he longs to be a man one last time by fishing a great fish.