His boss gave him an Axe and showed him the area where he was supposed to fell the trees.
The first day, the woodcutter brought fifteen (15) trees.
"Congratulations," the boss said, "Carry on with your work!"
Highly motivated by the words of his boss, the woodcutter tried harder the next day, but he only could bring ten (10) trees. The third day he tried even harder, but he was only able to bring seven (7) trees. Day after day he was bringing less and less trees.
"I must be losing my strength." The woodcutter thought. He went to the boss and apologized, saying that he could not understand what was going on.
"When was the last time you sharpened your axe?" the boss asked.
"Sharpen? I had no time to sharpen my axe. I have been very busy trying to cut trees..."
Moral: Most of us never update our skills. We think that whatever we have learned is very much enough. But good is not good when better is expected. Sharpening our skills from time to time is the key to success.