The so-called self-knowledge, for psychiatry, is a very important sign to judge the improvement of mental condition. Self-knowledge includes four aspects: 1) whether one can realize that others see this behavior or this mental state as abnormal; 2) whether one can realize that one’s own mental state is abnormal; 3) whether one can realize that such abnormal performance is due to a mental disorder; and 4) whether such a mental disorder requires psychiatric treatment. Self-awareness is divided into self-awareness and non-awareness. Patients with non-existent self-knowledge will have hallucinations and will hear some people talking about the world as it is really happening and deviating from the external real world. This will not think that they have a mental state and abnormalities, so this part of the population is called without self-knowledge.