When enough insane people scream in harmony that they really are healthy, they can actually start to believe themselves. Or put even more simply: people with overlapping delusions get along wonderfully.
Truth, Insanity, Delusion
Untraumatized people have a natural instinct to make healthy decisions in the best interest of their true selves. They are only limited by their immaturity and the brokenness of their external world.
Psychology, Self Help