You remember the Berenstein Bears, right? They're the perfect nuclear family of anthropomorphic animals who starred in many children's books like "The Berenstein Bears and the Messy Room," "The Berenstein Bears and Too Much Junk Food." There was even a cartoon based on the books out for a couple of years.
Problem is, you're remembering them wrong. It's spelled BerenstAin, not BerenstEin. I know. I know. After you've mopped up the brain splatter from the wall behind you, look at this:
It's true. Google it for yourself. It's always been spelled "Berenstain" with an A. At no point in time was Berenstain spelled "Berenstein." Chances are, your mind is just playing tricks on you; as a grown-up, you're so familiar with "-stein" names that you've retroactively changed your own memories. Of course, some aren't happy with that kind of explanation. They're so steadfast in their belief, and so convinced by the sheer number of people that swear it was spelled BerenstEin, that they've come up with what they consider to the only reasonable explanation: We're living in a different universe than we did when we were kids.
This theory has been around for a while, and recently cropped up again on NeoGAF. It explores the possibilities behind The Mandela Effect, which is the phenomenon of feeling like you have a real memory of something that didn't happen. The Effect's namesake comes from the common shared experience of thousands of people believing they read or heard about Nelson Mandela dying in prison -- even though that's not what happened. Remember that Tom Cruise movie Interview With a Vampire? It's actually called Interview With THE Vampire: The Vampire Chronicles.
Proponents of the theory are banking on the idea that everyone can't be wrong, but it's reality that's wrong. Supposedly, the cause of this sinking feeling is another parallel universe invading our space, and our own universe is reacting by absorbing parts of this new universe into its own being. Even though the universes are basically combining, the process of assimilation from the E Universe to the A universe is all but invisible to us. Decades-old books are corrupted, their spellings changed from Berenstein to Berenstain, right under our noses.
So the actual content is changed to Berenstain, the fact that we still see Berenstein everywhere from eBay listings to old TV Guides shows us that there's still part of us that remembers which universe we came from. If you really want to go down this rabbit hole, that blog post explores the theoretical physics of what's happening here. Just be prepared to spend the rest of your day thinking about it.
What do you think? Do you remember it as BerenstEin, or are you one of the invaders from a parallel universe that thinks it should be spelled BerenstAin?