Many on this subreddit (and elsewhere) mistakenly believe that "most myths and legends are either based off some semblance of truth or attempt to convey some message..." The belief that this is true can be regarded as a bit of modern folklore. Like many beliefs, it is often accepted as widely accepted and completely valid, but there is not evidence that at least the latter is true.

Folklorists Alan Dundes and Jan Brundvand independently attempted to "chase down" the original incident that inspired various modern "urban legends." They consistently failed. Where these stories came from is extremely difficult to fathom, even though most clearly are modern and one would think with all the tools available in a modern age, that it would be possible to track down to their point of origin - whether as a real incident or as a fabrication. Given those failed modern attempts, it is even more problematic to track down what an older story was "based on." In other words, we really need to accept, simply, that it was a good story that people told and retold, and where it came from is not likely to be known with any certainty.

That doesn't prevent people from attempting to find the "real" thing that was behind an older story. These efforts are always speculative. Some speculation is better than others and can be reasonably persuasive, but we cannot lose sight of the fact that in attempting to connect the dots between "this story" and this or that historic event/character is filled with speculation. It is a fun parlor game, but it is not anything that can be objectively accepted as fact. Good stories are, simply, just that, and we are all subject to a good story - and we like to repeat them.

Then there is the question of "what message does the story try to get across." Answering this, too, can be a matter of speculation, but it is perhaps speculation with a less problematic edge. Consider, for example, the international examples of supernatural being abducting babies. These stories can be seen as conveying a message to mothers to take care to watch their infants - always good advice. My work with Cornish mine spirits (knockers in Cornwall and tommyknockers in North America) puts forward the idea that miners were more likely to pay attention to subtle signs of timbers groaning if they thought it was a message from the supernatural: in short, the stories about these supernatural entities warning miners inspired miners to have a heightened awareness of conditions underground, and this might save their lives. This, too, is a matter of speculation, but I'm a little more comfortable putting forward these sorts of ideas - with the proper acknowledgement that they are speculative - because it is easier to watch the effect of these stories on how people act. Indeed, folklorists often refer to legends of this type as "warning" legends. This is a different level of speculation, separate from imagining connections with ancient events or people.

And even here, we can run into difficulty imagining what - if any - message is being conveyed. Cornish miners told of the danger of going underground after encountering a woman with red hair on the way to the mine. A prudent miner would turn around and go home to avoid the inevitable bad luck he would encounter underground. What is the hidden message behind this folk belief? Not wanting to open the door to dumping on our poor ginger brothers and sisters, I think we can conceded that the message here - if any - is more difficult to fathom.