One of my brother's friends I thought was kind of an idiot won a Fields medal for mathematics. Others of his friends have done impressive things, as well.

I will say one of my friends who was in a lot of trouble in high school straightened his life around, married a nice woman, and based on her influence became some sort of evangelical Christian (raised LDS). I would have said 50/50 he'd end up in prison. Most of my other friends have done more or less what I would have expected of them.