The wallet things seem to even out over time. I've returned a few to the owners or brought them to the police, and one time while riding, a guy in a car who I had never seen before pulled up alongside me and called me by name. He was holding my wallet, and recognized me from the ID photo.
My biggest life-saving deed was I deterred a flock of wild turkeys from crossing a busy four lane highway by screaming a weird noise at them, so they turned around and went back into the woods. I expect my Nobel Prize any minute now.