Mediocrity is a state of mind. We often feel inferior when comparing ourselves to other, more successful, people. We try to 'fit-in' and 'follow the crowd', whilst continuing to dwell on all of the bad things that happen in our lives. We don't realise that most other people lead equally unfulfilled lives, feel inferior, feel mediocre, and often put on a false front or adopt a pseudo-personality to either boost their own self-esteem, their sense of worth, or make others believe that they're doing better than they are. Ultimately mediocrity is linked to an overwhelming feeling of a lack of importance.
Agree.
Add to that that people don't think about you much (if at all) and the absurdity of the fear of standing out in the crowd becomes apparent. Sure, what the tribe thinks of you has been important in the stone age, but today...
People are too busy with their own lives and thoughts to think about you. Even if they've got nothing else to do but to form strong opinions about you and your behavior... do you really care?