Two stories to share.
1. When I was 12, I went with my Uncle to the hardware store. We stopped by the gun counter and I bought a box of .22 shorts. We went back to the house and I grabbed my rifle with the intention of trying out my new ammo on a few bushytails. I opened the box and discovered that the shorts were hollow points, which were 27 cents more per box then solids. I told my Uncle, and then said, "It looks like they made a mistake. Too bad.". My Uncle asked me if I wanted to go back to the store and exchange the ammo. It was "an offer that I couldn't refuse", Don Corleone would have been proud! Off we drove.
I walked back into the store feeling rather depressed because I had to give away my good fortune. The grandfatherly gentleman who rang me up studied the situation for a few moments, set the box back on the counter, turned to the shelf, and placed a box of .22 short solids next to the box of hollowpoints, and told me to take both boxes and see which ones worked better in my rifle.
2. While stationed in Hawaii, my buddy RP and I went into Kanaohe for diner. I found a wallet in the parkinglot of the restaurant, and it had 3 $1 bills in it along with a drivers license. I took the wallet and gave it to the cashier, and we sat down to eat. When we were finished we asked for the bill and we were told that the owner of the wallet had paid for our food. I asked if the $3 covered the cost of the bill, and was told no. But the 2 $100 bills that were hidden in the wallet did.
What comes around, goes around.