Sheldon: Anyway, the housekeeper in the faculty residence didn't speak any English. When I finaly managed to convince her I was sick, she said, "Möchtest du eine Darmspülung?" Penny: What does that mean? Sheldon: Based on what happened next, I assume it means, "Would you like an enema?"
If influenza was only contagious after symptoms appear, it would have died out thousands of years ago. Somewhere between tool using and cave painting, Homo habilis would have figured out to kill the guy with the runny nose