This happened to me about a year ago. I also have no clue how to format, so please be forgiving.
I worked in a grocery store (and I still do, but in a different department now), and at the time I was a bagger/cart pusher. It was a particularly busy day and as usual, we were out carts inside the store. I'm looking around the parking lot for carts when I hear the familiar rattling of shopping carts coming from behind me.
I turn around and to my surprise, I see a customer bringing up about 7 shopping carts!
The guy brings them up and says "Hey man, I figured y'all could use some help so I brought a couple of these guys from way out back" and he gestured toward the far end of the parking lot.
This random act really made my day, and really makes up for having to deal with dumb customers (not really).