A little boy was spending his Saturday morning playing in his sandbox. He
had with him his box of cars and trucks, his plastic pail, and a shiny red
plastic shovel. In the process of creating roads and tunnels in the soft 
sand, he discovered a large rock in the middle of the sandbox.

The boy dug around the rock, managing to dislodge it from the dirt. With
a little bit of struggle, he pushed and nudged the rock across the sandbox
busying his feet. (He was a very small boy and the rock was very 
large.) When the boy got the rock to the edge of the sandbox however, he 
found that he couldn't roll it up and over the little wall. Determined, 
the little Boy shoved, pushed, and pried, but every time he thought he had
made some progress, the rock tipped and then fell back into the sandbox. 
The little boy struggled, pushed, and shoved; but his only reward was to 
have the rock fall back, smashing his chubby fingers. Finally he burst 
into tears of frustration.

All this time the boy's father watched from his living room window as the
drama unfolded. At the moment the tears fell, a large shadow fell across 
the boy and the sandbox. It was the boy's father.

Gently but firmly he said, "Son, why didn't you use all the strength that
you had available?" Defeated, the boy sobbed back, "But I did, Daddy, I 
did! I used all the strength that I had!"

"No, son," corrected the father kindly. "You didn't use all the strength 
you had. You didn't ask me." With that the father reached down, picked up
the rock, and removed it from the sandbox.

Author Unknown