This is a really interesting rabbit hole, failing mainstream will attribute it to george orwells 1984 but the first mention I know of about 2+2=5 is from Dostoyevsky,

“I agree that two times two makes four is an excellent thing; but if we are dispensing praise, then two times two makes five is sometimes a most charming little thing as well.”

but it wasn't the man himself saying it, it was one of his characters loosely based on himself and what it meant was something along the lines of, "he is not the kind of person who would be happy living in paradise/order,(2+2=4) so he would rather live in a fantasy of chaos (2+2=5), they like to misquote this as if he actually said and meant it. It fits the narrative of the people trying to ruin our world because they couldn't live in a world of order and reasonability and want chaos where they can hide their scummyness in with the rest of the darkness. I am not a literary guy or anything I only just started reading real literature very recently so I may not be exactly right, also watch the old movie, "the gambler" with james kahn, It mentions the line and that is what made me start reading dostoyevsky, only after I read dostoyevsky's "the gambler" did I realize that the movie is loosely(very loosely) based on Dostoyevsky's book. These people are not just stupid, they are liars.