The number 13, black cats, breaking mirrors, or walking under ladders, may all be things you actively avoid—if you’re anything like the 25% of people in the US who consider themselves superstitious.
Even if you don’t consider yourself a particularly superstitious person, you probably say “bless you” when someone sneezes, just in case the devil should decide to steal their soul—as our ancestors thought possible during a sneeze.
Superstition also explains why many buildings do not have a 13th floor—preferring to label it 14, 14A 12B or M (the 13th letter of the alphabet) on elevator button panels because of concerns about superstitious tenants. Indeed, 13% of people in one survey indicated that staying on the 13th floor of a hotel would bother them—and 9% said they would ask for a different room.
On top of this, some airlines such as Air France and Lufthansa, do not have a 13th row. Lufthansa also has no 17th row, because in some countries—such as Italy and Brazil—the typical unlucky number is 17 and not 13.