The origins of a superstition
As unlikely as it may seem, it is simply because it follows the number 12 that the number 13 brings bad luck. And this since Antiquity, as Annemarie Schimmel, a teacher at Harvard, explains in her book The Mystery of Numbers. The 12 is indeed considered a perfect number: the 12 divinities of Olympus, the 12 constellations of the zodiac or the 12 labors of Hercules are all situations which give the number a perfect and sacred dimension, a symbol of completeness. In addition, there are the 12 months of the year, the 12 hours of the day and 12 hours of the night … As many occurrences of this figure which make it an important marker. And since 13 follows only 12 of 1, it is beyond completeness: it is deemed unreliable and opposed to the divine, and by extension malefic.