The Donkey and the River's Trick

A man had a donkey who used to carry his goods over long distances. On the way, the donkey had to cross a river. One day, he slipped and fell into the water. When he got up, he felt much lighter. What had caused the donkey to feel light? What will the donkey do to reduce his burden every time, and will his trick continue to work? Read this clever tale to discover the surprising lesson learned by the donkey!