One of the most abiding superstitions throughout history, that some numbers are lucky and others are unlucky. In our society, 3 and 7 are commonly held to be especially lucky; why this should be so is uncertain. Perhaps 3 is from the Holy Trinity, or it may have an earlier origin, such as the three-legged stool of the Greek prophetess Pythian. Seven may come from the seven days of the biblical creation, the seven ages of man, the seven deadly sins or the seven wonders of the world.
Thirteen as an unlucky number is even more puzzling, the more so because some communities regard it as lucky. Thirteen’s unlucky character may originate from the 13 seated at the table at the Last Supper: Christ and his 12 apostles, one of whom betrayed him.