A father came home from work tired and irritated to find his young son waiting for him. The son asked how much money the father makes per hour. Angrily, the father told the son $20 per hour. The son then asked to borrow $10, angering the father further. Later, the father realized he was too hard on his son. He gave the son the $10, but then the son pulled out some crumpled bills of his own, totaling $20. The son said he wanted to buy an hour of the father's time to have dinner together the next day.