effort is a good thing but knowledge and skills are everything

The engine of a giant ship crashed and the owners of the ship approached all the existing experts, searching for the bugs but to no avail. no One of them could not find out how to fix that engine .. After a great effort they found an old man working in ship repair since he was a young man and was carrying a large bag of tools with him,
When he arrived he began to work.
Check Engine accurately, from top to bottom.
There were two ship owners watching him eagerly and watching,
They wanted to know why the engine was broken and then repaired
He finished the examination, then went to his bag and pulled out a small hammer and quietly knocked on the part of the engine without any effort.
Immediately the engine returned to life and carefully returned the hammer to its place.
The old man said: I have repaired the engine!
A week later, the ship's owners received the repair bill from the old man
It was ten thousand dollars !!!!
But the owners of the ship were shocked and shouted "Impossible he hardly did anything"
Then they wrote the old man a note saying "Please send us a detailed invoice for the work."
The man sent the bill as follows:
Knock with hammer ............... $ 1
Find out where ............... $ 9999.00
It is knowledge and skill, not effort
The effort is important, but knowing where and when the effort is made in your life is making the difference