Suddenly acquiring a million dollars or more seems like a dream come true for most people, and in many respects it is. You are able to provide things for your children, for example, that you couldn't otherwise, like university tuition, which amounts to a small fortune these days. You are freed from the hassles of everyday bills, like car insurance or medical expenses. You can travel when and where you like. If you quit working, you don't have to be concerned about your job.
Initially, there is a great temptation to go out and buy things ... a bigger house, a fancier car, more clothes ... but before long you get over that. A deeper and more ongoing concern is how people relate to you, and how you handle the requests for loans and things, especially from relatives. And speaking of relatives, some of them will resent you, some will buddy up to you. You will likely lose some friends over the whole thing, although I guess you could say they probably weren't really your friends to start with.
You also have new problems you never had before, like how to manage the money so that it doesn't disappear when you're not looking, either through neglect or because of incompetent investment managers (which is most of them, in my opinion).