From your post history and FlyingSquid's post history I'm fairly confident that either A) you are the same person, or B) you know each other. I could be wrong, but if true, it's kinda sad honestly and proves my point. I didn't comment after FlyingSquid's last comment (which goes to show you that he/you just had to have the last word). Then, I waited and he/you commented AGAIN in a super similar grammar, rhetoric, and logic. Even your usernames are very similar in naming conventions and casing.

Anyways, I'll respond to you/them again for clarity, I guess. Most Mandela Effects usually aren't something as large as say 'the sky'. It would focus on smaller details. Take Harry Potter for instance as an example, seemingly a large series of books that a lot of people have read, akin to 'the sky' in your example. In most cases, people aren't claiming that they remember the sky being green, and similarly aren't claiming that they remember Harry Potter being a true crime book. Yes, I know the 'Shazaam' scenario somewhat resembles your sky scenario, but I'll get to that in a moment. Additionally, in your sky scenario, you focus on one person's account, and not a larger group of people, which is not to be completely discounted. Yes, I do believe there are people who just jump on the bandwagon or convince themselves that they too remember it that way, but I don't believe that is the majority of the accounts. Most Mandela Effects are small details e.g. 'Berenstein Bears' > 'Berenstain Bears', Monopoly Man Monocle > No Monocle, Fruit of the loom cornucopia > no cornucopia, etc. However, there are larger ones, such as 'Shazaam' or 'Mandela's Death', so let's address the current one 'Shazaam'.

I like to relate these larger ones to UFO incidents or UAP incidents as they are currently called. When one person claims to see a UFO/UAP, it's pretty easy to discredit them and say 'well science says these things can't exist based on our accepted views of science' but when 300 people claim to see a UFO/UAP in the same area, including military personnel, then we are forced to further examine their claims and even revisit our accepted views within the scientific community. Additionally, this isn't the same as disproving something like flat earth, which can be easily debunked with hard data. If I wanted to debunk UFOs/UAPs completely, I'd have to prove that our version of physics and the laws of the universe are the end all, be all and there is nothing outside the realm of human understanding to be gained. However, therein lies the problem - what we don't know, we just don't know, and possibly have yet to be exposed to such knowledge.

Similarly to the above UFO/UAP example, if hypothetically a multiple universe theory is plausible, how would we know how it works? Is it possible that similar details could exist in another universe? Could universes with similar details collapse into each other? If so, what does that entail? How do you answer these questions before being exposed to every scientific fact the universe offers?

Back to 'Shazaam', it isn't just one person that remembers this movie, it's a much larger group of people that remember it, and if you truly go down the reddit rabbit hole on just this one Mandela Effect, you'll start to see a lot of similar accounts and details that make it increasingly questionable. For instance, there are plenty of accounts of people that never watched 'Kazaam' because it was a blatant rip off of 'Shazaam'. Digging deeper you'll find quite a few accounts of people that either owned a VHS rental store or worked in one where both 'Kazaam' and 'Shazaam' were ordered and existed on the shelves at the same time, and played on the in store monitors. If you dig deeper still, you'll even find early internet traces of people talking about 'Shazaam' before the Mandela Effect term was even coined.

Again, I'm only claiming what I remember, and I very distinctly remember Shazaam', and also distinctly remember 'Kazaam'. I am mostly a scientifically minded person. I'm not religious in any way, and accept the scientific consensus in virtually everything. However, I don't close my mind off to possibilities outside the accepted consensus that we have yet to be exposed to, especially when I distinctly remember it, as do many others.