Heavily laden with groceries, my aunt asked a young clerk at the grocery store to accompany her to her car.  Arriving there, she unlocked and opened the doors and, without thinking, sat down in the back seat to check off her list of errands.

A moment later, the perplexed clerk walked around the car to my aunt.

"Lady," he said firmly, "I don't mind helping you load your groceries, but I really gotta draw the line at driving you home."