A passenger in a taxicab on the way to the airport gently tapped the driver on the shoulder to ask him a question. To the passenger's surprise, the driver let out a horrendous scream and nearly lost control of the cab, nearly striking a pedestrian and stopping just inches from a store's plate glass window.
"Oh my!" said the passenger, "I didn't mean to frighten you. I only wanted to ask a question. I'm sorry."
"No, no." replied the driver, "It was my fault. It was just a bit unexpected. This is my first day driving a taxicab. For the last twenty-five years, I've been driving a hearse."