Determination can lead a person to doing great things. Being determined can make you decide to do something great that you would have never done before in order to reach your goals. However, being overly determined can make you fail to achieve your goal. A person has to recognize the limits on what they can do before they attempt to do something. Santiago's extreme determination to reach his objective of catching the fish leads to his downfall. He did not know the limits to which he could reach. He pushed those limits too far. If he had done a few things differently, he might have been more successful.
Santiago refuses to take a rest during the whole time he is pursuing this huge fish. He becomes sloppy in his ways of trying to catch the fish. "I could just drift, he thought, and sleep and put a bight of line around my toe to wake me. But today is eighty-five days and I should fish the day well" (41). I think the fact that he has not caught a fish for so long has made the old man very determined. He feels that this is his moment to become a legend and save his career. However, while striving for these goals, he forgets that he needs rest and other things to keep himself sharp and well-aware of what he needs to do.
The fisherman's refusal to get help on this fishing trip also contributes to his downfall. He tells the boy, "You ought to go to bed now so that you will be fresh in the morning. I will take the things back to the Terrace" (23). Manolin is sypathetic to the fisherman's plight and is doing all he can to help Santiago be successful on his fishing trip, but Santiago does not want to take him with him. Manolin is not acting childish and there is no reason why Santiago should not be welcoming him to help. However later on during the trip, he wishes he had the boy there to help him. He did not plan out his trip well enough.
Santiago would have been more successful if he had realized that he has grown old and is more limited in his abilities then he was at a younger age. "It was too good to last, he thought. I wish it had been a dream now and that I had never hooked this fish and was alone in bed on the newspaper" (103). He has realized that he has reached his limits. He is now melancholy because he realizes that there is no way he will be able to get this entire fish back to shore completely intact and that his future might be bleak.
"You work now fish. I'll take you at your turn" (89). The fisherman is completely exhausted at this time. He has not slept since he went to sea and he has no one with him to watch the fish while he rests. The pursuit of this enormous fish has been long and has taken its toll on the old man. Santiago is no longer overly urgent in pursuing the fish anymore and is just waiting for it, sitting on the serene sea waiting for the moment.
Santiago mainly fails in bringing the fish because he refuses to recognize that he has limits. He does not seem to realize that he is an older man and cannot do all of the things that he used to be able to do. He refuses Manolin's help and with all of his determination, becomes blind to the fact that he needs to rest to be at his full potential. If he had been more thoughtful and less self-involved he might have achieved success.