Once upon a time their was a business man who conducted his trade with the help of his donkey. The merchant always traded salt. That was the old time, salt was one of the most expensive things in the market.
One time when the merchant and the donkey were crossing a river by a small wooden bridge the donkey slips and falls to the river. The donkey got up and started walking, surprisingly enough the load began to feel less and less.This was because the salt started to melt by the water that got to the sack.
After that the donkey made a habit, when ever passing the river dips his load and walks as easily as it can get. The merchant got really disappointed and wanted some solution to solve the behavior of the donkey.
Surely after a while he came up with the idea to load the donkey with cotton next time. As a habit even though the cotton was an easy load, when he saw the river couldn’t help himself but to jump to the river.
Surprising for the donkey instead of making the load easier the load became unbearable. But the merchant started to hit the donkey and yelling “move you smart-ass”. Guess who is smarter now. since then the Donkey even carrying salt never jumped to the river.
A lesson learned from your own mistake sticks up like a stain in your cloth that won’t come out that easily. The thing is any stain can be cleansed with the right detergent.