I think both generalizations are off the mark a bit. A lot of young folks are very idealistic and think they can have a larger impact (i.e. fix the world's problems). You also have those that are self-focused. Some of that is combined - focused on self means you may have an over-inflated sense of what you can accomplish and how your contributions will be received.

A lot of that is why some young entrepreneurs do go on to actually change the world (and we definitely need those people, although it isn't always for the best). But most that think that's what they are going to do fail a few times, and become more realistic in their views of what they can accomplish.

Sometimes the smarter someone is, the more quickly they can think through the possible results and come to those conclusions that they probably aren't going to be one of the few that does succeed to change the world, and that can (to the overall point here) lead to a sense of sadness and loss, maybe without having gone through the effort and failure, even. Which is a bit sad for everyone, because some percentage of those people probably could succeed if they just got out of their own way and stopped over thinking things, also.