Now that the Mayan apocalypse didn't happen, has anyone noticed another harbinger of bad news—an entire year ending in the number "13"? The Wall Street Journal finds little evidence of Americans fretting, and takes a lighthearted stroll through the history of the superstition. Some say that the fear of 13—known as triskaidekaphobia—dates back to Jesus having only 12 disciples or the Norse god Loki ruining a dinner by showing up as the 13th participant. Whatever the cause, the number keeps cropping up: