When an ice cream sundae cost much less than now, a young boy entered a coffee shop and sat at a table. A waitress put a glass of water in front of him.

The waitress brought the ice cream and walked away. The boy ate his ice cream, paid the cashier, and departed. When the waitress came back, she swallowed hard at what she saw. There, placed neatly beside the empty dish, were two nickels and five pennies -- her tip.
Author Unknown