My rational mind doesn't really believe in all of this, but if it did, I think I'd take Jacques Vallee's theory seriously. Jacques Vallee is an astronomer and computer scientist (involved in early ARPANET) who's studied the phenomenon since at least the 70s. Here's a fun paper:
https://www.scientificexploration.org/docs/4/jse_04_1_vallee...
He essentially argues that the UFO phenomenon is neither extra terrestrials nor merely misidentified aerial craft. It's something even stranger!
Also, if you find that paper interesting, here's one of this books (one of the most well-known in the anomalous phenomenon field):
https://www.amazon.com/Passport-Magonia-Folklore-Flying-Sauc...