When I was younger and we were struggling hard, we found a wallet in a store loaded with green bills. That money would have had immediate, real, positive impact for us, like gas money and food that we did not have. We turned in the wallet and did not bother counting the bills. The cashier might have pocketed the money, who knows. But hopefully the owner of the wallet got their stuff back. I think that act does cast a barometer on my and my wife's character. We did what was "right" -- the property was not ours and not ours to take. Did we feel good about it? Nope! It was just doing the right thing even though there was a touch of pain to it.
Occasionally I'll feel a twinge of guilt if I could've helped out and didn't but usually I do it out of habit.
A bit like when my dog begs for food, I'm not happy I fed him some pizza crust but I feel bad if I don't. It's self imposed guilt in both cases.
For e.g., around Christmas here in SF, I was a at a shopping mall parking lot waiting for my wife to return. I noticed a man counting a few bills of cash. He counted and then turned to head to his car. As he turned he dropped a couple of bills. I just shouted out to him to bring it to my attention so he could get it. I don't feel anything about the incident and would be hard pressed to use it as a barometer of my character.