my meta-narrative moments mostly had to do with reading comics as a kid, though i don’t think i necessarily understood them that way at the time. but comics are full of meta narrative tricks, from stan lee writing editor notes and jokes into the panels, superheroes crossing over to different universes for guest comics, and the way that certain stories are retold again and again, like the origin myths of major characters like batman and spiderman, by different writers and artists. the newspaper comics are also pretty self referential at times. i found a few funny images.
i think the first “serious” work of meta fiction that i read was “chimera” by john barth. when i was younger i just started reading all the books on my dad’s book shelf and found his first two novels, which are traditional sort of realism/modernism and really great books, but his career got very post-modern after that, and many of those books are really good as well. chimera is based on scheherazade from the thousand and one nights, and is a frame story with a bunch of framed stories in it, with like ten levels of embedded quotation marks of the speakers in each story telling the next story. its pretty trippy.