Awareness of Ones own Mediocrity

Some interasting statistics came up in psych class today. (i dont ememeber the exact numbers)  Most people consider themselves to be more inteligent then average (something like 90 %). Most teachers consider themselves better then average teachers. Most students consider themselves to be better then average student, most manegers beter then avarege managers and so on. I hope it is obvious that its imposible for most people to be beter then average. So then all these people are falsley confident in themselves.

Socrates said that what made him wise is not that he knew more then others but that he was aware of his own ignorance. Should the same apply here sould we try to be aware of our own mediocrity in order to not be ignorant and better ourselves? Or is this illusion and false confidence actually beneficial in keeping up our self asteam?