" The traumatic moment becomes encoded in an abnormal form of memory, which breaks spontaneously into consciouness, both as flashbacks during waking states and as traumatic nightmares during sleep. Small, seemingly insignificant reminders can also evoke these memories, which often return with all the vividness and emotional force of the original event. Thus, even normally safe environments may come to feel dangerous, for the survivor can never be assured that she will not encounter some reminder of the trauma. "

― Judith Lewis Herman , Trauma and Recovery: The Aftermath of Violence - From Domestic Abuse to Political Terror