In my firsthand experience, these guys are just LARPing 24-7. Try to imagine that. But the reality is they really can't do it full time. That's a lot of play acting. However, they still expect the world to indulge them in their delusions and god help us if we question anything.
And all of this acting, of course, takes its toll. Also, hormones that don't belong in you. But, yeah, I totally watched my roommate prematurely age and get (really) fat and also "perform" vocal tics around me, pile on tons of makeup and just get really caught up in this ideology/religion.
What this boils down to is just Narcissism, but (of course) no one wants to be diagnosed or labelled as a "Narcissist" because it's a shitty, selfish disease and it can't be "celebrated" like some other diagnoses. And there's quite a conundrum there.