He was suffering from mild depression during his college years with the feeling of being unfulfilled and frustrated from being a perfectionist.
Contextual Analysis. John Nash, being diagnosed with paranoid schizophrenia, greatly affected his behavior as abnormal. He was often seen acting as if talking to somebody while alone. He also often caught behaving as though he was in an unexpected commotion. All of these were courtesy of the delusion he had established in associating while hallucinating with characters he alone can see. His hallucinations dealt with characters he has been seeing and dealing with since he was studying at Princeton University, to the period where he was hired in delusion by the fictional top secret agent that led to the severity of his illness as it harmed himself and the people concerned with him.