A common mistake in the thinking often brought on by psychosis is the incorrect perception that one's thinking is clear and accurate. If the mind is malfunctioning, one can not properly evaluate the quality of one's thoughts.
Things may suddenly seem to make sense that before were baffling. A person might get the perception that they have embarked on a new and better level of consciousness. A psychotic person might believe he or she is spiritually enlightened or has special wisdom.
(Sometimes it is not easy to know for sure whether one's thinking is actually on the mark, versus the illusion of that.)
The idea that the thinking is inaccurate may be the last thing that occurs to a psychotic person. You can't usually convince a delusional person that their perceptions are inaccurate--they almost invariably won't listen to that. The delusional brain causes a state of mind in which direct evidence that contradicts delusions is ignored. A psychotic mind often has bizarre interpretations for things that would otherwise be taken at face value.
Delusions can convince a person that they are famous (delusions of grandeur) that people are "out to get me" (paranoid delusions) that people can hear one's thoughts (thought broadcasting) or other odd and incorrect beliefs.
The belief that oneself is "a psychic," can know things without directly observing, being told, or through surmising, is yet another assumption that quickly leads to deterioration. Being a "psychic" doesn't mix well with being psychotic.
With experience and practice, we don't have to repeatedly "get bitten by the same dog." If a person who suffers from psychosis can learn from his or her mistakes, the same error does not have to unendingly repeat. Once someone acknowledges that they have been deluded, they can begin working toward correcting that.
When I had my last round of severe psychosis (caused by stopping medication against medical advice) the recovery afterward was much harder than that of previous psychotic episodes. I was working with a brain that had begun to age and that had been through a lot.
Upon reinstatement of medication, it was quite an uphill battle to get back to a "normal" state of mind. It really helped me to have the realization that my thoughts weren't correct--the realization that my mind was lying to me. This might seem obvious, yet to a psychotic person it is like a revolution in thought.
The thoughts and the beliefs we have are often the product of our assumptions. If we assume we are perfect, it doesn't allow for the correction of errors. If we incorporate an assumption that the mind can deceive us, it causes natural self-correction to take place.
Without medication, a person with schizophrenia suffers from a "hardware" problem. This means that nothing gets processed correctly. Once the hardware problem is to an extent corrected with medication, the person is left with the "software" mess that had been generated when the brain was malfunctioning. Medication may bring the hardware of the brain into a workable zone, but it does not correct errors that were generated before being medicated. This is where talk therapy and contact with other human beings is useful.
For some people with schizophrenia, delusional thoughts are pleasurable. Additionally, the schizophrenic person may be obsessively attached to a delusional belief and cannot let go of it. The spiritual growth work that I have done over the past thirty years helps me not be too emotionally attached to a false belief.
The mechanisms by which ordinary people remain "sane" tend to be social ones, or may be assisted by news and entertainment. Most people can not guide their thoughts strictly on their own observations. I rely on my wife for a lot of my "reality checking."
My two books, "Instructions for Dealing with Schizophrenia: a Self-Help Manual," and "Jack Bragen's Essays on Mental Illness," are available for inexpensive download on Amazon, or can be purchased from there in paperback. I can be reached with your comments at: firstname.lastname@example.org