The greatest obstacle to being heroic is the doubt whether one may not be going to prove one's self a fool; the truest heroism is to resist the doubt, and the profoundest wisdom to know when it ought to be resisted, and when it be obeyed.
At a restaurant do you order what you know is great, or do you try something new? Do you make what you know will sell or try something new? Do you keep dating new folks or try to commit to someone you already met? The optimal balance for exploring new things vs exploiting them once found is: 1/3. Spend 1/3 of your time on exploring and 2/3 time on deepening. It is harder to devote time to exploring as you age because it seems unproductive, but aim for 1/3.