Trauma means wound, injury or shock, and although many people think of trauma as an event, whether an event is traumatising depends on the effect it has on the person, not on the event itself. A healthy personality depends on our ability to integrate various aspects of our experience. The three integrative actions of synthesis, personification and presentification may happen more or less unconsciously, but they require energy and our ability to do them varies with circumstances. Synthesis describes the mental actions that bring different elements of our experience together. In the simplest form there is one elaborate the apparently normal part of the personality (ANP) and one, often rather rudimentary, the emotional part of the personality (EP). The classic example is post-traumatic stress disorder (PTSD), where the ANP gets on with life, until the EP, which holds the traumatic memory, bursts through, creating what are commonly known as flashbacks.