I dabbled in this subject a bit. I do remember it being "berenstein" not " Berenstain " bears. And I'm a person who is pretty good with words and spelling, even from a young age, so that was a bit strange. I actually even went and got and old hardcover book from 1982 I believe, and sure enough, it was "Berenstain " , which basically got me looking into it more.
As for the movie references , which are a few, I'd like to see the VHS versions before I form an opinion. The darth Vader quote doesn't even sound right the way it's supposed to be now. " life is like a box of chocolate" without the "s" doesn't sound at all like I remember. "Mirror , mirror on the wall" is how I remember it, not magic mirror on the wall. Mr rogers ... I remember being "it's a beautiful day in the neighbourhood" not " it's a beautiful day in this neighbourhood".
I think a lot of the Mandela effect can be chalked up to peoples bad memories, or should I say, not perfect memories. I don't doubt this could be a huge psyop experiment on the public to gather data and to cause confusion, and I don't discount the possibility that cern firing up the lhc at crazy intensity of power could have shifted our reality.
With the new developments of things such as neural lace and AI, who, if anyone actually successfully has implanted in themselves, would have and iq light years ahead of us and could easily, easily create a Mandela effect scenario for who knows what purpose. Sounds to me like someone is just trying to keep us all confused.