The Mandela Effect was introduced by a wild-eyed paranormal who is into hunting ghosts and believes in fairies. I believe it is a demonic deception. It has formerly sane people convinced that they are drifting between alternate realities or timelines. It has some Christians thinking the Bible's sitting on their shelves-- not just on google-- are being constantly changed.
I believe it is a clever demonic strategy that of course has some human sociological and psychological elements to it. Here is how I think they do it.
1. Find numerous facts that people remember wrong, brand names that were spelled wrong on some products, etc. Find stuff that the minds of a certain percentage of the population will remember wrongly because it is not important to us.
(e.g. it's Berenstain Bears not Berenstein Bears, Jif Peanut butter, not Jiffy, "No, I am your father" not "Luke, I am your father." Sally Field, not Sally Fields. a loop you never noticed on the Ford emblem. Froot Loops, not Fruit Loops.)
2. Have videos posted that show all these shocking facts all at once.
3. Propose an explanation. E.g. CERN experiments creating an alternate time line, in which the historical record is edited, and most people remember it differently from you because they are from this time line or the Matrix has edited the glitch in their mind but not yours.
5. Throw more facts that the person that they were sure was not the case. E.g. the person sees something on the map that is different from what they remembered (in some part of the world they've never visited, for example). A demon projects thoughts about how that is not right into the individuals mind.
5. Provide a peer group that insists the world is changing. Other YouTube or blog posters insist that the Bible really said something else, that some part of the map was different, or that the movie quote as it exists on video now is 'wrong'. Instead of being surrounded by people who help you out by looking at your crazy and make you feel foolish for believing this stuff, you are surrounding by people online who support you in the delusion. You an face derision for not believing people are falling through multiple universes. This is a powerful tool in drawing people in.
6. Give the individual hallucinations, or false memories. If you read online, there is someone who claimed while they were searching Berenstain Bears, a screen shot of Berenstain Bears was edited on their hard drive as the residuals of the old reality were edited away. I know of someone else who took a screen shot of the one outlier, the one version of a Bible verse that was the way he remembered, unlike the other entries on the screen. Then the screen shot and google search on the screen changed to conform to other Bible verses. He perceived this was demonic activity at work either in his mind since he'd sensed a demonic presence when he'd viewed these videos earlier.
This philosophy is dangerous. If someone believes in it, he could be overcome by fear. If your family isn't really your own, just one from one of millions of alternate timelines, that can cause social and emotional problems. If you think reality is coming unglued around you, that could lead to some serious mental and emotional issues. Also, convincing people that their Bibles are changing is also quite dangerous. I've heard some rather demonic interpretations of passages from the Bible looking into this.
If you want to look up the Mandela Effect, I'd encourage you to pray and get some direction from the Lord on it first, and don't allow your mind to be deceived by it if you look at it. There is bound to be some fact out there you were sure you remembered wrongly.
And, of course, if you were sure it was 'Luke, I am your father' but you know it was Jif and not Jiffy and you have no idea about the Berenstain (versus 'stein') spelling, the theory is unfalsifiable. Followers can just tell you that you are from one of one of many multiverses, and in your universe, Jif was Jif and Darth Vader said, "Luke, I am your father."
The theory has enough pseudo-science behind it to attract some skeptics, since some physicists have used the multiverse theory as a counterexplanation to the evidence for design and the astronomical chances of life being able to exist.
I wonder though why these people don't tell stories of waking up and saying 'where's my second naval?' or 'where's my laser blaster?' No, it's name changes and spelling, and also entire continents, which are huge, but small things to remember wrongly. Why would consciousness shift between universes? That makes no sense. Why would entire living beings shift between universes instead of just a few atoms in the legs and arms. Why a whole brain or mind? It doesn't make sense.