Is this anything like Jumbo Shrimp or
Military Intelligence?
Sure you merely mean 'myth'; for a 'false myth' would equal truth!
Not necessarily. Of the following definitions from Dictionary.com, I was using it in the definition #2 sense.
2. A popular belief or story that has become associated with a person, institution, or occurrence, especially one considered to illustrate a cultural ideal: a star whose fame turned her into a myth; the pioneer myth of suburbia.
3. A fiction or half-truth, especially one that forms part of an ideology.
4. A fictitious story, person, or thing: “German artillery superiority on the Western Front was a myth” (Leon Wolff).
I could have assumed the #3 or 4 sense, but that would leave open the possibility that someone would presume it in the #2 sense, so I qualified it with the word, "false" to avoid confusion. Ha! A lot of good that did me.