Complex PTSD is the main topic of Stephanie Foo’s memoir. As of the book’s publication, it was not recognized as a diagnosis by the Diagnostic and Statistical Manual of Mental Disorders (DSM) in America. It is distinct from regular PTSD in that it is not the result of one specific instance of trauma but builds up over a longer period. It is difficult to treat because there is no foundational trigger to address. Child abuse is a common cause of C-PTSD.

Dissociation is a mental state in which an individual feels disconnected from their body and the world around them. It is a common form of self-protection for people who experience trauma: Dissociating allows them to ignore violent or unbearable conditions and ensures their survival. It is therefore a common coping mechanism for those with PTSD and complex PTSD and can manifest as flashbacks, trances, time loss (or blackouts), amnesia, out-of-body experiences, etc. Dissociative identity disorder (DID) is an extreme form of dissociation. Foo at first did not believe herself to be dissociated, even when remembering her past, because she felt rational and secure rather than detached or shut down. However, she eventually realized that her emotional distance itself could be a mild form of dissociation: In attempting to run from her past, Foo prevented herself from processing her trauma.