Once a little boy, old man and their donkey traveling on feet.

First passerby "What morons, they have donkey and no one is riding on it. So boy sits on donkey.

Second passerby "Look, what a shame, young lad sitting on donkey and poor old man is forced to walk on feet. So they swap.

Third passerby "Wow, this grownup adult is riding donkey while little kid is walks in hot sun. So they both sit on donkey.

Fourth passerby "Amazing, just amazing, two able bodied people riding on this poor animal. Can't they at least take turns like a decent human."