A relatively new to me concept I've been running into is that of "memetic virus", intentionally constructed by human hands, that, if implanted at opportune times in the right minds would cause a conflagration of an irrational thought to spread around the world.
Richard Dawkins mentioned something alike this in his "viruses of the mind" essay https://en.wikipedia.org/wiki/Viruses_of_the_Mind but his discourse was limited to denigrating the religious and seemed to miss out on the bigger picture, that being, that if it were possible to ingrain a meme onto people's minds that one day, someone would use it as an instrument of mental war.
I've read many anecdotes of people going off the deep end with political stuff over the last 6 years or so, people who refuse have a reasonable conversation about or seem to be unable to explain their convictions that bad thing was actually good thing even when shown evidence to the contrary.
How did we go from relatively peaceful in the 90's to a maelstrom of insanity in less than 30 years?
If it were one person or a certain group of people, it might make sense, but this memetic virus seems to have spread worldwide, infecting almost everyone, and since our frame of reference is also infected we can't see that we're infected with it.
Is there a cure? I wouldn't know. Is there a defense against it? I don't know? Does it actually exist or is it a convenient cover story that I can blame all the woes of the world on? Once again, I don't know.
I really don't know if this is true, but I suspect that if you brought a group of average people from 2000, 1990, 1980, & 1970, I feel like they would all agree that the world has gone mad and that there must be some reason for it.