Nails in the Fence

There once was a little girl who had a bad temper.  Her mother gave her a bag of nails, and told her that every time she lost her temper, she must hammer a nail into the back of the fence.

The first day the girl had driven 37 nails into the fence.

Over the next few weeks, as she learned to control her anger, the number of nails she hammered into the fence each day gradually dwindled.

She discovered it was easier to hold her temper than it was to drive the nails into the fence.

Finally, the day came when the girl didn't lose her temper at all, and she went to find her mother...