As a youngster, my suitcase fell out of a rental car trunk onto the highway in Florida. Someone stopped, got it, actually took it to somewhere on Disney property, turned it in, and Disney shipped it to my parents' house and it arrived a few weeks later. That took effort from multiple people. And nothing was taken from my bag, either (not that there was anything to take).

Another time, I locked keys in a rental truck, and a random woman gave me a ride. And a guy in an office let me use his cellphone to call to get the keys out of the truck.

A random guy passing by helped me lug a car battery once, when I had an injured foot and was limping.

Yet another time, my phone slipped and fell on a plane, and I heard it slide somewhere. Someone sitting by me noticed and got people in the rows around me to hunt around and find it.

I always try to help people when I'm in a position to help them. I've returned wallets, helped people find things, helped people on airplanes, etc. I tried returning a Kindle I found once, I assume/hope the person got it back. Amazon was not very helpful about it. The person who lost it was kind of weird about it, too (they left it in an airport bathroom).