I knew a guy who made a boatload of money off of the dotcom bubble. He kept doubling down and doubling down, then at right about the peak he told himself "I have as much money as I'll ever need if I cash out now. There's no reason to take any more risks." In other words, he timed it perfectly (based on his own situation - he wasn't genius and he would freely admit that)
So here he was, a multimillionaire who'd spent the last five years or so working and playing the market to the exclusion of everything else. He was one of those people who had unconsciously believed if he just had enough money he could find a way to be happy. When he finally had the money he realized relationships with other people are what make you happy. But at that point he didn't have any friends and didn't know how to make them.
He was, without a doubt, the most miserable guy I've ever met. He was always willing to buy a round or lend people money. He'd go to Vegas and pay for five or six people to go with him. So there were always people around. There were always women willing to sleep with him. But they were there for the money and he couldn't delude himself into thinking otherwise. The money actually added to the problem, because it meant even when he wasn't paying, people had a motive to hang around. So he became cynical and a bit paranoid.
Eventually he got into drugs and ended up eating a whole bottle of pills. I've always wondered if any of those hangers-on went to the funeral.