Just for posterity
The Mandela Effect is just false memories + the sleeper effect.
The mechanism is that when you imagine something that happened in the past, at first, your brain can easily tell the difference between the real memory and the imagined scenario. But that imagined scenario gets stored much like a real memory does.
Over time, the "metadata" decays--it becomes harder to distinguish the real memory from the imagined one. The weaker a memory, the more vulnerable you are to being misled by false memories.
like
Do you remember how it rained during your prom?
imagine that
imagine it really hard, visualize it, tell me some details about it
10 years from now, you won't be so sure it didn't rain.
Sounds like a nice, tidy, and perfectly sensible explanation. But is it correct in being "just" that? Surely some of the reported differences are just this or even full blown psychosis in action, but in your guts and expanded awareness you're working on are you certain?
Folks are willing to fight over this stuff. The bible stuff alone is enough to cause some serious Strife indeed.
The reason the False Memory effect is so pervasive about events that happened 10+ years ago is because the mind is so suggestible. All it takes to generate a false memory is a leading question.
This is the reason that there was a whole "Satanic Ritual Abuse" scare in the 90s.. therapists at the time were big into "recovered memories", and would ask children leading questions at what they suspected happened. "Did you ever see satanists in the woods?" -- "Did the satanists do anything to you?" Kids think about it, and gosh, they do remember something now that you mention it! Lots of people went to jail over this, the head of the american psychological association (Elizabeth Loftus) proved that these forms of testimony (based on children's memory recovery) are unreliable at best, and basically had to flee to Australia because she got a lot of innocent people (assumed to be satanic child abusers) out of jail. And you know how we hate that.
This is why leading questions are not allowed in court. If you ask somebody "Was there a big red stop sign at the intersection?" they will say yes, like, 30-40% of the time, even if there was no stop sign. If you don't lead with that image, and just ask them to describe the intersection, very few people report a stop sign.
Every article I've seen about the Mandella effect asks leading questions. They will say "Remember the Berenstein bears? Turns out it's always been spelled Berenstain." They lead with the false information first, and suddenly, you can't distinguish the weak memory of how that word is spelled and the image you just visualized.
In my gut, do I think this explains all of the Mandella effect phenomenon? Yes, actually. I haven't seen a single instance of the Mandella effect that can't be explained via false memory, misinformation, or the simple conflation of two elements you barely remember. Not to mention, lots of trolls have generated images that make it more confusing.
Honestly, what do you think is more likely? That people have trouble remembering forgettable media and news items from 20 years ago, or that we're in a bizarro universe where history changes, but only about super minor things like Sinbad's acting career?
I think it's much more likely that memory is fallible and is not an exact record.