| Quote #19
Because the old man speaks alternatively to himself and to the fish, it is at times unclear to which he is speaking. This suggests there is not a lot of difference between the old man and the fish,
Even after the fish is dead, the old man’s is determined to finish the job without rest.
| Quote #20
Despite overwhelming odds against him, the old man never gives up until the very end.
The old man recognizes that, although practically there is nothing he can do, he will still fight for the sake of enduring.
| Quote #21
Although he "knows the fight is useless," the old man continues to battle the sharks anyway. This suggests he is fighting for some other motivation than "winning."
When Santiago’s strength fails him, he simply waits patiently for it to return.