I used to marvel at people who would come into a sum of money they had never seem before- the first thing they would do is go out and buy a car, usually something that would have far less value in five years than something off the lot. One of the worst investments EVER! Pretty soon, they have a POS used car and nothing else. One guy snorted his inheritance and lost his house, marriage, kids......ended up flipping burgers for quite a while.
I'd give it a shot, though- I'm approaching retirement and would start by finding some places to donate it to, then invest a good chunk. At this point, $500K would be enough for me to do a lot and have a great time without becoming some kind of weird hoarder.
I don't know if it's a matter of people never being taught about handling and investing money, but a lot of people seem to be completely clueless, as shown by all of the debt consolidation loan and credit card ads. One ad for a card shows a happy couple and the guy saying "We paid off our credit cards and bought a boat!". That's one of the worst things someone can buy if they can't manage their finances- boats are great and I enjoy boating a lot, but one thing makes it different for me- I know how to repair boats and if I can't do it, I know people who can, having done that kind of work for a living. If someone doesn't know which end of a screwdriver to pound on, owning a boat requires money- a lot of it.
I hate debt. I still owe a bit for my house, but that's all.