Question: Why is Jerry Lee Lewis known as "The Killer"?
Answer: Many people assume that Jerry got his famous nickname because of his wild and often violent nature, but the fact is that Jerry Lee had a habit of calling acquaintences "killer," the same way we might say "buddy" or "dude." (This was not an uncommon use of the word for a man in North Louisiana in the postwar period.) So the name stuck to Jerry... to this day, he greets some folks with the appellation "killer" (usually, it is said, when he's forgotten their names!).
