Vecna is a memory thief theory 🕓🧠
(this is not a new theory by any means, I just wanted to write my take on it because I’ve been thinking about it all day, mild spoilers for ‘the first shadow’ and the s5 trailer)
In season 2 When Will is hospitalised at Hawkins Lab following the tunnel incident, Bob finally is told the truth about everything that’s going on. He’s clearly in shock, nothing like this ever happens in Hawkins right? Or at least that’s what everyone thinks, so of course Bob had no idea what was going on, and Joyce says he’ll most likely have to sign NDAs like everyone else and never talk about it to anyone outside of the group.
This scene makes perfect sense with everything else we’ve been shown up until that point, Bob is almost standing in for the audience here, a lot of us could relate to his statement as that’s probably what we’d say too in that situation, finding out about the upside down.
However in season 4 we learn about Vecna, how he’s been the one behind it all, almost every weird thing that’s ever happened in Hawkins dating all the way back to the 50s as a young Henry Creel.
It’s established that he can look through memories, and that’s how he picks his victims (possibly even why Will was sent to the upside down in season 1, he was chosen, it wasn’t coincidence) he looks for people who are already struggling, easy targets, less likely to run.
In season 1 we see Dr. Brenner testing Elevens abilities, it’s shown again in season 4 with the other children, and we know he did these same tests on Henry. Each child seems to have slight variations in these abilities, so with Henry being able to access memories it’s not much of a stretch to assume Brenner trained him to erase unwanted ones, like government secrets etc.
He clearly wasn’t aware of anything strange going on, however in season 4 we learn about what happened in the Creel house in 1959, Bob was 12 when this happened, and would have heard about it. It’s clear the details were at least somewhat publicly known too, as when Wayne Munson sees what’s happened to Chrissy in his trailer he immediately connects the dots. So Bob surely would have remembered something so horrifying that happened in his small town when he was a kid right?
Okay well maybe he didn’t learn the details, maybe he just thought it was a normal murder I mean it was 25 years ago so maybe he genuinely just forgot right? WRONG! How could he just forget?? His adopted sister Patty was in a relationship of sorts with Henry Creel, one of the supposed ‘victims’ of the supernatural crime!! His goddamn sister!!!
Bob is shown to be intelligent, Bob The Brain, he obviously would have looked into what happened in the Creel house and he would have remembered it!! He wouldn’t have said what he said to Joyce, would he have been shocked? Yes, but not completely thrown off, he would have probably immediately recalled what happend in 1959. This is if he still had his memory of it.
Now I’ve not seen “the first shadow” stage play yet, I really want to so I’m not gonna spoil myself too much but that’s where we learn about his sister and her relationship to Henry, and I also know that Bob, Joyce & Hopper were all investigating bizarre happenings in Hawkins, so he DID know there was weird stuff going on, so why is he suddenly clueless?
Well because Henry has obviously wiped his memory of it, as well as Joyce and Hoppers, however it seems Hopper’s more aware than he lets on. We all know by now how big of an inspiration Stephen King was on the Duffers when creating Stranger Things, and in IT there’s a similar concept with memories, almost an inverse actually.
The adults in IT just completely forget about all of the weird stuff once they leave Derry. Only Mike, who stays, can remember and he has to jog the memory of the rest of the losers club. And in Hawkins all of the adults just seem to have forgotten about all of the weird stuff from their childhood, but Hopper, who has spent the most time away from Hawkins, seems to know the most. 
He seems to be remembering things in season 1 and that’s perhaps how he manages to evade issues with Hawkins Lab, striking a deal with them, maybe he had information they needed regarding what happened in 1959, idk?
He somehow manages to get them to leave El alone and after he goes looking for her in the woods then takes her to his cabin to live with him… he MUST know something, I think he’s the most clued in out of all the adults.
We know he’s teamed up with El in season 5, perhaps he has knowledge that will help her to defeat Henry but we’ll just have to wait and see.
Anyway~ mini rant over, I wonder if anyone actually read this whole thing lol
This could maybe also explain ‘birthday gate’ as well as why Vecna started his killings after Mike left for California.
Mike is the only person I can’t quite understand forgetting Will’s birthday, it’s so out of character for him. Especially with him visiting for spring break, it was clearly planned that he’d be going for Will’s birthday, and yet he just forgets?
Mike definitely has a lot of trauma, he’s a perfect fit for becoming a Vecna victim so he was definitely looking through Mikes memories. Vecna would have seen that he was planning to visit Will and Eleven for spring break, and we know those are the two characters Vecna has the most interest in.
Making Mike forget Will’s birthday would break him, he probably feels so alone especially since everyone else seemed too preoccupied to remember either. But Mike forgetting would probably hurt the most, especially since he went to visit him during it and had no idea. Making Will even easier to manipulate, giving him fresh trauma that Vecna can use against him.
This could be why Vecna started his killing spree after Mike left, Will and El would obviously try to save their friends and come back to Hawkins, so having Will feel like his friends don’t even care about him in time for him to get back to Hawkins would help Vecna break him down even further so Vecna can get in his head and possibly turn him against the group.
It could even be a contribution as to why Mike was acting so weird in the airport, he’s forgotten how to act around Will, forgotten how much he cares. And possibly even why Mike has stayed with El for so long despite not loving her back, making him forget his love for Will.
I’ll keep adding if I think of more stuff, this is just a personal little hypothesis collection now I guess.
