Psychogenic fugue is a rare psychological disorder
in which a person whitewashes their entire identity - including home, job, friends, and relations - to invent themselves anew. The transformation is so complete that the person is unable to recall any elements of their actual past. It simply doesn’t exist. They are, for all intents and purposes, an entirely different individual.
The transformation occurs suddenly, without warning, and is caused by extreme levels of psychological stress. The peak moments of Post Traumatic Stress can oftentimes serve as a catalyst. Hence, sufferers are typically veterans, rescue workers, or survivors of intense natural disasters (such as 7.0+ earthquakes). Oftentimes they are experiencing intense martial problems. Fortunately though, most cases remain relatively short lived.
An excellent cinematic depiction is David Lynch’s Lost Highway, in which the main character, played by Bill Pullman, undergoes a fuguesque transformation after being sentenced to deathrow for the mysterious murder of his wife. A tenor sax jazz musician, he transforms into a 24-yrold auto mechanic who lives with his parents (played by Balthazar Getty). Granted, this is all wrought with staple acid-test Lynchian surrealism, but the director himself has admitted that the disorder was the prime inspirational force behind the plot.
However, in contrast, note that the unnamed narrator of Chris Palahniuk’s Fight Club does not suffer from psychogenic fugue. The creation of Tyler Durden is an ongoing process that, at times, brings the two personalities into direct contact with one another, hence being more of an extreme case of Dissociative Identity Disorder than a self-effacing transformation.
A limited form of psychogenic fugue is frighteningly common on the internet, where everyone seems to suffer from some sort of intense psychological stress, and changes identities like Proteus on LSD.
Just take a real close look at everything.