Two ditch diggers were deep in the ground digging a ditch. A supervisor was sitting at the top of the hole in a chaise lounge reading the newspaper. Ditch digger one said to the other, "why is it that we are down in this hole digging this ditch making $10 an hour, while the supervisor gets to sit in a chair and read the newspaper while he probably making twice as much as we are?" They both contemplate the question but neither could come up with logical answer. Finally the second ditch digger looked at the first and says, "why don't you go up there and ask him!" After climbing out of the hole and approaching the supervisor the first ditch digger say, "Hey boss... Why is it that you get to sit in this chair and read the newspaper while my partner and I are down in the hole really working hard and only making half of what you make?" The supervisor replies, "well - it's because I have intelligence!" The ditch digger thinks for a second and says, "I'm not sure what "intelligence" means. Could you explain it to me?" The supervisor says, "sure I will. And when I'm done you need to get back to work! Deal?" The ditch digger agrees and the supervisor says, "follow me..."
The supervisor reaches a nearby solid brick wall and puts his hand against the wall. He tells the ditch digger to hit is as hard as he can. The ditch digger smiles, winds up and delivers a crushing blow to the brick wall - just as the supervisor moves his hand away. The supervisor tells the ditch digger that his demonstration should satisfy his curiosity and he needed to get back to work. The first ditch digger, a bit confused and hurting from the punch to the wall thanks the supervisor and heads back to the hole. After he climbs back into the hole he is approached by the second ditch digger who asks, "well? Did he explain it to you?" The first ditch digger responds, "Yes he did - he has 'intelligence'!" "Intelligence? What's intelligence?". Beaming from ear to ear because he knows the answer, the first ditch digger proceeds to put his hand in front of his face and tells him "here. let me show you! Go ahead! Hit my hand just as hard as you can!!!"