What is the implication in broader terms; do we EVER stop having to prove ourselves(according to Hemingway)?

Santiago was a great man and age has caught up to him. He is mocked by the younger fishermen and feels he must prove himself yet again. Our society demands youth and strength. Wisdom and age are rarely respected. In this context the aged feel the need for validation. Great sports stars, like Santiago's idol Joe Dimaggio, are not supposed to grow old and decrepit. I think we only stop proving ourselves when we decide to opt out of the mainstream belief of youth and power above all.