Nasruddin was returning home from the market, and his donkey was carrying bags of salt.
On the way, they had to cross a stream. The donkey slipped, and the salt dissolved in the water. When the donkey stood back up, he found his load was lighter, and he trotted happily home.
The next time they came from the market, the donkey was carrying bags of wool. He decided to stumble on purpose but, instead of dissolving, the wool absorbed the water and weighed even more than before.
"You can't expect to get lucky every time!" Nasruddin said to the donkey.
Inspired by: The Exploits of the Incomparable Mulla Nasrudin by Idries Shah, free to read online at the Idries Shah Foundation.
Notes: This is story 13 in the book. The same story is in Aesop's fables, although instead of wool, the donkey is carrying sponges the second time: The Donkey with the Load of Salt. This illustration is from an edition of La Fontaine's fables; La Fontaine tells it as a story of two donkeys, one carrying salt and one carrying sponges. The illustration is by Grandville: