A fish, which you can't see, deep down in the water, is a kind of symbol of peace on earth, good will to yourself. Fishing gives a man... some time to collect his thoughts and reaarange them kind of neatly, in an orderly fashion. Once the bait is on the hook and the boat is anchored, there's nothing to interfere with thinking except an occasional bite
The old man and the boy & The old man's boy grows older (ed. 1989)