What Makes A Genius?

A genius has every right to be extremely self-confident. Some geniuses - such as Richard Wagner, Friedrich Nietzsche or Orson Welles - were almost megalomaniacs. I sometimes wonder what comes first - the tremendous achievement or the huge self-confidence. The latter seems often to be the pre-condition of greatness. Would a humble Wagner have dared to defy the rules of the classical theory of harmony? Would a modest Nietzsche have declared the death of God? Would a shy Welles have been able to co-write, produce, direct and star in his very first film, Citizen Kane? I don't mean to say that immodest people are bound to become great. Most are not, although they usually succeed more easily than others. You do have to have great talents. On the other hand I've met very talented people who just were lacking the self-confidence to assert themselves against mediocrity, tradition and arrogance. Maybe they just would have needed a bit of megalomania to become great.