[D_Alex]

>What are the people who were "gifted" but live a mediocre life supposed to do? Be bitter and drink for 40-60 years?

It is hard to give a brief yet universally applicable answer to "What are _____ supposed to do?", but neither "be bitter" nor "drink" is right.

The best advice I know of is "take well thought out action in pursuit of a worthwhile goal", which of course raises the question of what a worthwhile goal might be. Fortunately, there are many such goals, you don't have to worry about picking the very best goal. Health, fitness and education related goals seem like a good places to start, they will improve the capabilities needed to reach future goals, whatever those might be.