Gee, Mike. I figure that if there's something "in control of life" out there, he/she/it can chose to make our lives miserable any time he/she/it wants, including the 13th day of the month when it falls on a Friday. But I suppose that's up to he/she/it, not me.
And efcharisto or thanks to El Greco for the history and Greek lesson. Triskaidekaphobia is how I always heard it, too. As for origins, I don't remember 13 being flagged in ancient Greek as a bad luck or ill-omened number. But it's been a while since I was reading that stuff.