Completely random.
So I was in a line at a McDonald's drive-thru about a month ago. A little stressed on my way to a log home project and getting the quick breakfast to pack some carbs. It was gonna be a hard day with a lot of high work, and cold.
I placed my order then drove up to the first window with my money ready to pay.
The McDonald's employee said "you're good to go, the person ahead of you paid for your order, random act of kindness".
It was a simple thing but caught me off guard and really made me feel good that morning, kinda restored a small amount of hope that I have for humanity.
I randomly did the same thing to someone unknown behind me in line the other day.
There ya go.