It always strikes me as odd that most of us don’t even know the origins of everyday words that we all use, much less the origins of holidays and supposedly “bad luck” numbers, items, and days.
Most people are unaware that each day of the week is named for an ancient God or Goddess sacred to our forbearers. (Monday is Moon Day, generally personified as a Goddess, Tuesday is Tyr’s day, the Norse God of war… etc.) We live in a culture that is somewhat isolated in time – we celebrate some holiday traditions but most of us just skim the surface, not knowing or caring why. Or perhaps even sillier, many people continue to believe that their favorite holy day has something to do with their favorite contemporary religions (Christmas, Easter, etc). Despite the signs they put in their lawns, it’s simply not true. Contemporary religions subverted and/or borrowed holy days from older beliefs.
But back to Friday the 13th.