I don’t give a damn whether people call themselves Stoics or not and whether they’re sincere—whatever that means—or not, but I’m very sure, specifically, that there are a lot more fans of Meditations than people who’ve read it or even meaningfully read about it, which is funny in that “oh boy, aren’t we humans goofy” sort of way. It’s also an easy phenomenon to stumble on innocently while trying to discuss the book, though I think that goes for a lot of Very Important Books that more people claim to have read than actually have. IIRC someone wrote a whole tongue-partially-in-cheek guide to pretending at having read books, for the reason that it’s pretty common.