The very best shaggy dog stories are almost believable. Farfetched most definitely, highly unlikely, certainly. The really good stories, the excellent japes, those so believable as to make fools of us all last for eternity, develop a tradition of their own, become more than tall tales, they become legend.
Mine own particular favorite is of course the 1957 Panorama skit of the spaghetti harvest in the tiny Swiss Tyrolean canton of Ticino. Possibly the most famous, or perhaps infamous piece of tomfoolery ever perpetrated upon the innocent and still quite gullible television audience, a ruse that resulted in numerous national newspaper headlines at the time and still echoes historically and upon YouTube in grainy black and white to this very day.
As stated in that well known literary masterpiece, “The Court and Character of King James”, written by Anthony Weldon in the year 1651, the Italians having a logical proverb, “He that deceives me once, its his fault; but if twice, its my fault”.