The boy rode on the donkey and the old man walked. As they went along, some people remarked "it was a shame the old man was walking and the boy was riding". The man and boy thought maybe the critics were right, so they traded places. Later, they passed some people who said, "What a shame, he makes that little boy walk."
They decided they both would walk.
Then they passed some more people who thought they were stupid to walk when they had a decent donkey to ride, so they both rode the donkey.
Finally, they passed some people who shamed them, saying "How awful to put such a heavy load on a poor little donkey".
The boy and man realized that those folks were probably right too, so they decided to carry the donkey. As they crossed a bridge, they lost their grip on the animal and he fell into the river and drowned.
Lesson:
If you try to please everyone, you will eventually lose your ass.