Here's an example of how quickly and easily these legends take on concrete status: Several years ago I was talking to a guy I knew at my church. Somehow in the conversation it came out that my hobby was metal detecting. He proceeded to spin a fabulous tale of a treasure he knew about. In a cave, that he had actually been too. And that in the 1930s or 40s, human bones had been found in the cave, with had a suit of armor on one of them! And so it was a supposed hidden treasure of one of the California missions, along with a fabulous tale of a massacre by the indians to cover the trail, blah blah blah. And he was dead serious that he knew where this cave was now. He'd hiked there as a younger man, and could take me right to it. We'd need ropes to descend down in, etc...
The more I pumped him for information, it finally dawned on me what he was talking about: It came from a local writer, who writes mostly fiction:
Randall A. Reinstedt | Barnes & Noble
But a few of his books weave true historical accounts, with the rest being "fill-in-the-blank" conjecture. And one particular story this author had written, told the story of a cave discovered south of Big sur, where, in fact, skeletons *had* been found. And one *had* been of European descent (the rest were indians). And early speculation dreamed up fabulous tales of a hidden treasure or mine or other-such-nonsense. And in fact, later on, it got cleared up that the bones of "european descent" found there with the indians bones, were more-than-likely a worker from the 1930s, from when the Hwy. 1 cut through there, who had passed away. His body must've been put in there, as a convenient, uh.... grave. Found 20+ yrs. later, only-to-turn into this fabulous conjecture. It takes on a life-of-its own, and now, presto, you have a treasure legend.
It was just one of many such stories (conveniently failing to give the alternate explanation of the road worker being the one set of bones), that Randy puts in his books. The books are nothing more than fun books for tourists to buy at tourist traps here. Or fanciful stories that you read to your kids.
BUT MY POINT IS: Even though I happen to know this story is not at all a "treasure", yet .... do you SEE how easily grown adults, who would claim "critical thinking", can just gobble this stuff up, and take it as gospel fact ? Heck , there was probably a "faded newspaper clipping" to allude to. And heck, then you just combine that with another speculation of mission treasure, make note of how it was on a trail they used, then throw in a drawing of a man in Spanish armor, and .... by golly .... it HAS to be true. Afterall, it's in print !