Found a dollar bill outside a convenience store. Walked inside and spent it on a Powerball lottery ticket, all on a whim. Guess what? I won the lottery.
True story.
But here's the less interesting part: I only won four dollars of the several-million-dollar lottery. So, no, I didn't win the whole shebang.
Here's another story:
Found a five dollar bill on the floor next to one of those bargain book bins at Barnes and Noble. Looked around, said, "Hey, did someone lose this?" No one paid much attention, and there didn't seem to be anybody searching for their lost cash. I figured, what the heck, not my money, so I picked it up and set it in plain sight on top of a book on the edge of one of those bargain books (as you may recall, I had just won the lottery, so I didn't really need the money...). Then I noticed a woman across the store watching me -- sort of a I-noticed-her-outta-the-corner-of-my-eye thing, as opposed to a I'm-staring-at-you-directly kinda thing, which may explain what happened next. I walked away to browse some nearby books and surreptitiously watch the bill. No surprise, that woman who had observed me from afar came and snatched up the bill. Maybe it was hers.
Here's one more:
Stayed at a Florida motel years ago when I was kid traveling with my family. The day we were leaving, I found a roll of bills on the sidewalk in front of another room. Picked it up, unrolled it: four dollars. I knocked on the door in front of which I found the money. No one answered. I knocked again, louder, longer. No answer. I waited. Still no answer. I kept the money.
More recently, I found a penny in a parking lot yesterday. I kept it. (My lottery windfall having long since been spent...)