I've been reading lots of John Keel after having watched Hellier the tv show.
Hellier got me into a booklist that featured Keel but have been tumbling down the rabbit hole ever since.
Keel is famous for the ultraterrestrial take where he postulates that cryptid sightings/aliens/ghost/demons/angels etc are all representatives of the same entities or entity (the ultraterrestrial). That over the years this entity (or entities) has shown itself to us in various ways to influence our behavior.
He found that there is little difference in the mind of someone who has been abducted by Aliens vs those that have been demonically possessed. That the UFO pattern fits our technological level of design.
We all know of flying disc UFO. But the flying disc UFO were famous in the 50s (coincide with plane development at the time). Before that there would be planes flying with wings too small to hold their frames in the air, or airplanes flying in the early 1900s at night before the Wright brothers had even flown 100 yards in the day. That even before that there were blimps flying between major cities in hours and I mean like in california to Chicago type of distances. And before that there were men in suits flapping their wings and flying across the country. We only got out of the 50's flying disc UFO sightings after star wars was released and the v shaped star destroyer ufo's started appearing.
What is more interesting is that this is all cyclical. He had broke it down just by newspaper and television reports that he could accurately predict whenever they would show up. Wednesday at 10:00pm is the most popular time to go outside and try to see something. Check it yourself.
The reason we can never find bigfoot/find a downed ufo/find a cryptid like mothman is because these creatures only temporarily exist in our realm. Then they are disassembled and thrown back into the ether until they need to show up again.
Of course newspaper clippings and reports from the TV aren't the end all of proof, they can be hoaxed, but if you read into it long enough the sheer number of coincidences and things start to make lots of sense.
Of course, whenever Keel was introducing his theories, was in the 60's, 70's, so there is plenty of stuff he just didn't know about, but it is still interesting.
If you do pay attention to this kind of stuff, you will start noticing things that are crazy though. Bigfoot and ufo combination, supernatural and ufo combination. Cryptid and all three combination. Shows like skinwalker ranch will make you think that skinwalker is the only place this kind of stuff happens all together but it literally happens everywhere, all over the world and the US. People just don't pay attention to the areas it happens in. Utah, Colorado, Missouri, Alaska (state only has 700,000 plus people, yet 16000 people have went missing since the 80s), New York (Hudson River Valley might as a whole be more active than the Uinta basin). Grab your tin hat, fire up Hellier on Amazon Prime, grab you some Charles Fort, Jacques Vallee and John Keel and travel down the rabbit hole.
Before John Keel I thought the Men in Black were a secret government agency designed to protect humans from Alien entanglements, but there are also different mib who were guys who barely acted human, could barely hold a conversation, didn't know how to eat human food and disappeared on dead end streets if you tried to follow them in brand new cars that were ten to fifteen years old.
A guy had been investigating a UFO flap (a flap being an outbreak of UFO sightings) and was starting to leave when he felt that he needed to do something. He went back inside and started to rearrange his bookshelf. After a couple of minutes he thought that was good. Got in his car and left. This put him perfectly in time with a head on collision with a train. Had he not listened to an internal desire to rearrange his bookshelf he would've missed the train easily. He only remembers being slightly out of his head then, like he was on autopilot. He survived with no major injuries but didn't investigate the flap any longer.
It at the very least is giving me a ton of writing ideas.