I have a better definition of Myth: “What never was true, and always will be.”
LOL, that’s pretty good, I’m going to use that.
Did you ever read the book “The Daughter of Time” by Josephine Tey?
It is novel, one of a series about a police detective in England. In this book he has been severely injured (I think he fell through a skylight or something) and is laid up for several months. Out of boredom he “re-investigates” the murders of the “tower princes” by Richard III.
It it most interesting and gives many good examples of “myths” as per your definition.
Consider The Franchise Affair and Brat Farrar as well.
Cheers!