A salt seller used to carry the salt bag on his donkey to the market every day.
On the way there they had to cross a stream. One day the donkey suddenly tumbled down the stream and the salt bag also fell into the water. The salt dissolved in the water and the bag became lighter. The donkey was very happy.
He started to play the same trick every day. The salt seller came to understand the trick and decided to teach the donkey a lesson. The next day he loaded a cotton bag on the donkey. Again he played the same trick hoping that the cotton bag would also become lighter.
But the dampened cotton became very heavy and the donkey learned his lesson. He didn't play any tricks after that day and the seller was happy.
Moral of the story: Luck won't always favor.