Lots of people think that the number 13 is somehow unlucky. There are those, however, who develop a fear of the number 13 that goes far beyond simple superstition. There is even a name for this fear (phobia). It is called paraskevidekatriaphobia, or friggatriskaidekaphobia. (I’m NOT kidding.) Specifically, these phobias relate to a fear of Friday the 13th but do encompass other fears related to the number 13. These phobias are more common than you might expect.
Some trace the notion that the number 13 is unlucky back to the Last Supper. Judas Iscariot (who betrayed Jesus) was the 13th person to sit down at the table of the Last Supper.
No matter what the origin of the superstition that the number 13 is “unlucky” a great many people accept this as fact and avoid the use of the number 13 as much as possible. Of course, it’s a little difficult to completely avoid the number 13 since it is the number that comes between 12 and 14 no matter what you do.
Still, most hotels do not have a 13th floor. Well, actually they DO have a 13th floor, but it is named the 14th floor. The number 13 is simply skipped. The floor directly above the 12th floor is the 14th floor in most hotels around the world.
Even if the owners of the hotel are not superstitious, they recognize the fact that a great many people are, and many would refuse to stay in a room on the 13th floor.
There is no 13th floor in most government buildings. Of course, those who see conspiracy everywhere just naturally assume that there really IS a 13th floor, but that the government is using it for nefarious purposes.