Actually, the origins of Friday, the 13th are complex, a mix of both realities and myths:
The date itself is an extension of the fear of the number 13, known as paraskevidekatriaphobia, which was heavily popularized by fiction writers back to the 19th and 20th centuries and extending, of course, by our own love of the 1980 horror flick, Friday the 13th...and its many haunting extensions.
The date is shrouded with many myths...or at least unknowns. There's the actual number 13 traced back to several sources such as Judas who supposedly was the 13th guest at the Last Supper before betraying Jesus. In medieval times, the actual day of Friday was thought to be an unlucky day to begin any important work.
The reality is evidenced in events such as that on Friday, October 13, 1307, King Philip IV of France ordered the mass arrest of the Knights Templar. Hundreds of these powerful medieval knights were imprisoned and many were later executed.
With that as background, and since, in fact, it is Friday, the 13th, let me shift to the many myths surrounding the profession of Sales since most of these end up costing salespeople unnecessary time, but more importantly are on the wrong side of the equation for building trust and value creation with the prospect.