In 1986, I suffered a psychotic breakdown. With support from the staff at Fulbourn Hospital, I was able to overcome my illness. My mental health had been blighted by fearful dark delusion and associated alarm for 15 years. As I recovered, I developed my own interpretation of psychosis and have constructed a personal theory that attempts to give form and structure to a nebulous and very disturbing state of mind. My theory is of the existence of an active and directive rogue psychotic mindset; hereafter referred to as the RPM. I would define this mindset as being a body of nonsensical thoughts, ideas, beliefs, suppositions and assumptions that occupy a volume in the mind. This body of cognitions is given credence by being tentatively linked to the factual world. It is active in the sense that one is influenced by its rogue contents. As such it is directive and can drive not only one's thoughts, but also one's behaviour. Other normal mindsets co-exist cerebrally with the RPM. Such mindsets serve to tip the balance and normalize behaviour. During and after psychotic breakdown; in the absence of clinical psychology knowledge, my RPM developed as I struggled and tried to explain the unusual experience of going psychotic.