Aesop's Fable: Donkey and the Merchant

A Merchant, driving his Donkey homeward from the seashore
with a heavy load of salt, came to a river crossed by a shallow
ford. They had crossed this river many times before without
accident, but this time the Donkey slipped and fell when halfway
over. And when the Merchant at last got him to his feet, much
of the salt had melted away. Delighted to find how much lighter
his burden had become, the Donkey finished the journey very
happily.

Next day the Merchant went for another load of salt. On the way
home the Donkey, remembering what had happened at the ford,
purposely let himself fall into the water, and again got rid of
most of his burden.

The angry Merchant immediately turned about and drove the
Donkey back to the seashore, where he loaded him with two great
baskets of sponges. At the ford the Donkey again tumbled over;
but when he had scrambled to his feet, it was a very disconsolate
Donkey that dragged himself homeward under a load ten times
heavier than before.

Moral:

The same measures will not suit all circumstances.
Counter old tricks with new ones.