Late 1980s I was working in a grocery store. I looked down and saw a large wad of cash on the floor. I picked it up intending to take it to the front desk which was standard for finding lost customer property. I counted the cash. It was over $600. At the time that was a small fortune to me, but I never considered keeping it.
But on the way up front I passed an older woman who was crying "my money, my money," while she emptied everything out of her purse searching desperately. I knew I had found her money, so instead of taking it up front I handed it to her saying, "Ma'am, I think I found your money on the floor back there. Here ya go." She, of course, was very happy. I might have felt even better than she did about it, though.
Now, to prove that I'm not perfect (as if anyone thought that,) many years later I bought a few items at a WalMart self checkout. Upon retrieving my change from the machine, I realized there was more than there should have been. Not a fortune, mind you, less than ten bucks. Rather than turn it in I kept it. I still feel guilty about that to this day, probably 20 years later.