I have the impression that most 'smart' people (at least, college-smart) have lived most of their lives thinking (quite rightfully) that they're the smartest person in any given room.

Such mentality may work quite well for the first 25-30 years of their lives. But then they'll be put to work with other people just as smart as them, and they'll be unable to collaborate constructively.

Some people are able to realise this breakthrough moment in their careers, and improve on their own. For the rest, I wish college had prepared them more specifically for intellectual humility.