Once upon a time there was a peddler who slowly travelled to the seaside to buy salt. After he bought the salt and was on his way home he ambled across a river. When he was half way across his clumsy ass tripped. Because the load was salt it dissolved and became very light.
The next day the fairly angry peddler went back to the seaside to buy more salty salt. Because the tricky ass remembered the day before he purposely tripped again. When he got up the load was lightened again. The donkey, who was very pleased with himself, laughed as donkeys do. He did this two more times, then the peddler had a plan!
The clever peddlers plan was to buy sponges instead of salt. When the silly donkey tripped on purpose, because the sponges got unbearably heavy with water the donkey had twice the load. Which makes the moral of the story: laziness doesn't pay.