This paper uses a case study of my own experience to explore the cause of my schizophrenia. The aetiology is presented as a particular trauma that is seen as being at the root of the problem. What is relevant is not so much that a trauma occurred, but the fact that elements were present in the traumatic experience that created an on-going division between reality and a false belief, which I have termed as ego-divisive situation. I found myself divided in my mind between two understandings of reality. The result was the formation of a false reality, which became internalised at the conscious level and the real facts of the event remained hidden in my unconscious. My hypothesis is that such a dual understanding of ‘reality’ may often be present in psychosis and that the distressing emotional components are present in the unconscious, helping to maintain the split reality. I suggest that these cognitive and emotional dual realities, ambiguous, ambivalent and traumatic can thus be the reason why a person becomes psychotic. This hypothesis is supported by a detailed description and analysis of my experience.