Sometimes, when people lose a limb, they still experience, sometimes in a painful or bothersome way, sensations in the missing limb.
In a similar way, aspects of the person who goes through trauma may be missing, cut off, from their conscious awareness, but still intrude upon the person at times. It’s as if there is a longing for wholeness; those missing aspects want to connect to the whole person, but are not able to in the same way as before. If they can’t find their way back in peacefully, they might crash into the traumatized person’s life or experience in some disturbing form, such as flashbacks, self-mutilation, compulsive sexual acting out, or other things we in the psychotherapy world refer to as “symptoms.” The cut off pieces might be sensations, perceptions, memories, feelings, or aspects of their “personality.”