It has simularities too prodject montauk, prodject monarch, hence why the narrator always mentions "jack" jack is cage backwards, it seem it all started with his hypnosis secret room shit, and the jack and jill stuff hence the multiple personalities.
When after watching the movie fight club, you begin to question whether your best friend is a real person, or an alter ego your mind has sub-conscientiously created.
Joe: (walks in) hey man, wanna play some Madden?
Dan: (points gun at himself)
Joe: Uh.. Dan.. why are you holding a gun to your head?
Dan: Not my head Joe, OUR head.
Joe: Uh-oh, Fight club syndrome.
When a couple has sex so loud and hard that sheetrock falls from the wall and any person(s) in the apartment or house where the sex act is taking place cannot sleep, watch TV, or anything else due to the distraction. Derived from the film Fight Club, when Tyler Durden fucks Marla Singer so hard that the whole house shakes.