A couple of years ago, while I was on my way to work, my car developed a flat tire. I think it was August - I know it was hot, and I just didn't want to try to change that stupid tire.
Luckily for me, a couple of Good Samaritans stopped, the husband repositioned my jack (I had gotten that far) and changed the tire for me. He didn't accept any payment but my thanks.
Today I got a chance to make a difference in someone else's day in a positive manner. I had stopped at the post office to check my PO box and as I was walking back to my car, a man hollered at me asking if I could give them a jump. I said I could, if they had jumper cables. (They did.)
So, they pushed the car over by mine and got to work. After a few minutes, several tries and changing over to the heavy-duty jumper cables, they got their car to start. The driver asked if he could give me anything, and I said no. Later it occurred to me that it was sort of my payback for the assistance I had received with the flat tire.