Now do i think he is mediocre? No way! Even as a husband only him can tell that, maybe not even his wives. Nobody know how hard it was for him to be in a marriage, or even get to marriage in the first place.
Take again an small entrepreneur from Brazil, India or Africa in a small village. Are they mediocre? Sure, low money, not visible for the world, no New York Times covers.
But how hard it really is to be a entrepreneur when all the education you had when you was a kid was how to ask for money in the streets?
There's no mediocrity there's just this illusion created by the very riches and powerful to make even more money, to create a crazy game to make us feel bad and always keep charging for the carrot.
In the end of the day, it's your job to respect everyone limitations, including yours, and never judge the guys next to you as mediocre, or yourself. You may not get in the history books, but a lot of people around you that need you and your "mediocrity" wont read then anyway.