Seriously, this is the greatest joke I ever head.

There once was a little boy named John, and when he graduated from preschool, his father was so proud that he said to the son, "I'm so proud of you! I'll buy you anything you want!"
"I just want a pink and purple polka-dotted ping pong ball." The boy said.
The father did as he was asked.
One year later, Jon graduated from Kindergarden. The father said, "I'm so proud of you! I'll buy you anything you want!"
The boy simply answered, "Ok, all I want is two pink and purple polka-dotted ping pong balls."
The day did as the boy asked, buying him the balls.
When he graduated from the 6th grade and was ready to go to Junior High, his father said "I'm so proud of you! I'll buy you anything you want!"
The son smiled and said, "All I want is 100 pink and purple polka-dotted ping pong balls."
A bit baffled, the father did as he was asked. After finishing 8th grade, the boy was ready for high school. The father was glowing with pride, and said "I'm so proud of you! I'll buy you any video game or whatever you want!"
The boy just said, "All I want is 1000 pink and purple polka-dotted ping pong balls."
The father bought the balls for him. Four years later, John graduated high school. John was the man's oldest son, and he was so proud that he had graduated and was going to go to college. He told his song, "I'm so proud of you! I'll buy you anything. I'll buy you a car or pay your college tuition. Anything"
"Thanks, Dad, I just want 10,000 pink and purple polka-dotted ping pong balls."
The father was glad to buy them for the son.
Four years later, John graduated from college and was ready to enter medical school. "I'm so proud of you! I'll buy you anything you want! Tuition, a house, an SUV! Anything!"
John said, "Thanks, Dad, I'd like 100,000 pink and purple polka-dotted ping pong balls."
The father bought them for the son as asked. Three more years passed, and the son graduated from medical school at the top of his class.
The father had never been prouded, and said "I'm so proud of you! I'll buy you anything. I'll pay for your wedding or for a place for you to start your own practice!"
The son smiled and said, "All I want is 1,000,000 pink and purple polka-dotted ping pong balls."
Two weeks later, the father and son were driving in a car when they got into an accident. Both were pinned under the car, and knew their time was running short. They were both going to die.
Finally having to know, the father asked, "Son, before we die, I must tell you how proud I am of you... and I have to ask, what did you do with all those pink and purple polka-dotted ping pong balls?"
Taking a breath, the son answered, "Well, Dad, I -" And then he died.