Oliver is one of those kids who doesn't mind going to the dentist. He brushes his teeth every day, goes for check-ups, and hasn't ever had a toothache.
It is after school and Oliver is calmly sitting in the dentist's chair having his regular check-up.
The dentist is looking at Oliver's teeth, gently poking and prodding. So far, it's looking good - no cavities, no problems.
Suddenly the dentist stops and says, "Would you mind screaming as loud as you possibly can?"
"But why?" says Oliver. "It doesn't hurt at all."
"I know," says the dentist. "I have a waiting room full of patients and the basketball game starts in an hour!"