Heard this somewhere.

A little boy asked his father, who was always busy with work, "Daddy, how much money do you make per hour?"

The father was a little surprised, but glared at the kid and replied, "Now why would you want to know that? Don't bother me now, I'm tired."

"Daddy, please! Just tell me how much money you make an hour."

The father relented and said, "Twenty dollars an hour."

"Okay, Daddy. Then can you lend me ten dollars?"

"Is that why you wanted to know how much I earn? Go to your room and don't bother me anymore!"

Later, as the father thought over what he said, he started feeling a little guilty. Maybe the kid just wanted to buy something. So he went to the kid's room.

"Hello son, are you still awake?"

"Yes."

"Here's the money you asked for."

The son took the money, pulled some more cash out from under his pillow and started positively jumping with joy.

"Thanks, daddy! Now I have enough, now I have twenty dollars!"

The father was confused and stood there gazing at his son until the boy said, "Daddy, can I buy one hour of your time?"

What can I say. Ouch.