One of the ways we keep ourselves from succumbing to the madness of others (folie a deux- a madness shared by two), is to constantly remind ourselves of what is real, what is true, and what is the actual human consensus, and we can only do that by having regular discussion with those who are NOT mad.
People thrust into environments where they are encouraged to believe or do things against their nature or common sense, will eventually succumb to delusion, if they’re not capable of touching base with those not in that environment. (You can see this in the movie Get Out, for example. Where Chris is being encouraged to do and believe things that his best friend, who is not there, keeps cautioning him against. Chris’ friend are the “words of wisdom” that eventually save his life, and without his warnings, Chris would’ve become just another victim.)
We all need to understand the nature of the madness so as not to fall to it.