If everyone actually knew how little they know, they wouldn't be cocky.
There's nothing wrong with being self-assured in what you do know, and honest about what you don't, but cockiness does seems to be a good indicator of an individual's ignorance of his (or her) own ignorance.
I mean, become a cocky bastard who also knows his/her stuff, and have all the fun, rather than whining about how the cocky bastards have all the fun.