"A scientific fact" (Smoking's not bad for you)

CUSTOMER: "Do you have a cigarette I can bum?"

ME: "Sorry, I quit . . . broke free!"
CUSTOMER: "Why?"
ME: "Not good for me . . . I'd rather not die of lung cancer."
CUSTOMER: "That's a myth."
ME: "A myth?"
CUSTOMER: "If you smoke in moderation there's nothing bad about it."
ME: "What is moderation?"
CUSTOMER: "Ten a day."
ME: "So half a pack a day is good?"
CUSTOMER: "No harm in it."
ME: "I have a difficult time believing that."
CUSTOMER: "It's a scientific fact. Research and science proves it."
ME: "Where did you hear that?"
CUSTOMER: "On the radio."