While I do agree that it’s generally true that Darkners “believe” that their spontaneously generated backstories actually “happened” to them, it is vital to keep in mind that this is not universally true. Just as Darkners are aware of their existence as fantasies, NPCs whose purpose is to assists Lightners, we have examples of Darkners acknowledging their fictitious pasts and actively making “arbitrary” decisions about the details of their own stories:

Just as it is true that Darkners cannot be so easily pigeonholed into categories of “personhood” and “nonpersonhood”, “real” or “not real”, to “know” a Darkner’s history is not as simple as finding out what is “real” or “not real” in the Darkner’s mind. The Darkner’s memories are tied up in the same illusory dark fountain magic that governs their physical forms and the world around them.