I like a story I read on facebook about a man teaching his son loosing his temper....
Every time he lost his temper, he had to go hammer a nail into a fence...... over time, he put in fewer and fewer nails. Then, his dad had him PULL the nail out each time he said something nice, or helped someone (or something like that.. I don't remember the full story...)
Anyway, as time went on, he eventually pulled all the nails out of the fence... dad and son went out to look at the fence, and all of the growth he had accomplished... but... as the father then pointed out... no matter how sorry you were for saying things, or loosing your temper, you can never take back what you said or did.... look at all the nail holes in the fence... those scars are there forever.....