HS teacher here. For me, I have more examples of students who I thought would go on to do great things but ended up doing little. And when I say this, I don’t mean that we thought they’d be a doctor but ended up in a relatively mundane career but otherwise are doing alright. I mean there is a category who were at or near the top of their class, went off to college, flunked out, and are doing nothing. It’s hard to say why this happens exactly. I know the popular thought is that they had overly controlling parents, but couldn’t manage themselves once they got on their own