Two men were digging a ditch on a very hot day. One said to the other, "Why are we down in this hole digging a ditch on such a hot day, while our boss is sitting in the shade?"
"I don't know, " responded the other. "I'll ask him."
So he climbed out of the hole and went to his boss. "Why are we digging in the hot sun while you just sit under the shade of this tree?"
"Intelligence," the boss said.
"What do you mean , 'intelligence'?"
The boss said, "Well, I'll show you. I'll put my hand on this tree and I want you to hit it with your fist as hard as you can."
The ditch-digger took a mighty swing and tried to hit the boss' hand. The boss moved his hand just in time and the ditch-diger hit the tree. The boss said, "That's intelligence!"
The ditch-digger went back to his hole with a sore hand. His friend asked, "What did he say?"
"He said we're down here because of intelligence."
"What's intelligence?" said the friend. The ditch-digger put his hand on his face and said, "Take you shovel and hit my hand."