Most people can't manage 50 cents let alone 50 million.
I have become adept at making money, not because I wan't a flash house, expensive car, jewelry or anything like that but rather I readily accept the 'responsibility' of managing money and redistributing it, from people that are irresponsible (buy useless crap) to those who use it more wisely, (help other people).
If I came into a large sum of money my job would instantly become that much more complicated and a hell of a lot more work.
The funny thing about money is that the vast majority of people want more, no matter how much they have.
What most don't realize is that money can be a real curse especially if you let it become your master instead of mastering it.
To answer your question, it would not change me at all.
I would still drive the same car, still live in my poky unit. The only thing I would do that I haven't done is set up businesses abroad so that less fortunate people can have a job making stuff westerners commonly take for granted.