There once was a little boy who had a bad temper. The father gave the child a bag of nails and told him that every time that he loses his temper, he must hammer a nail into the back of the fence.

The first day the child had driven 37 nails into the fence. Over the next few weeks, as he learned to control his anger, the number of nails hammered daily gradually dwindled down. He discovered that it was easier to hold his temper than to drive those nails into the fence.
Finally the day came wen the child didn't lose his temper at all.

He told the father about it, and the father suggested that the child pull out one nail for each day that he was able to hold his temper. The days passed, and the young child was finally able to tell his father that all the nails were gone.

The father took the child by the hand and led him to the fence. He said, "You have done well, my child, but look at the holes in the fence. The fence will never be the same. When you say things in anger, they leave a scar just like this one. You can put a knife into a person and draw it out. It don't matter how many times you say "I'M SORRY", the wound is still there. A verbal wound is just as bad as a physical one".