['I was in the park the other day and dropped some money on the ground without knowing it. A kind stranger witnessed this happen and picked up the money. That person then returned it to me.']
That's so awesome. Isn't it so nice when people do nice things for each other in their communities?
I dropped money on the ground in public.  A kind and honest stranger saw me drop it and returned the money to me.  I trusted that person after that.