Freud writes: "The overestimation of one's mental capacity, which appears absurd to sober judgment, is found alike in insanity and in dreams, and the rapid course of ideas in the dream corresponds to the flight of ideas in the psychosis. Both are devoid of any measure of time. "The dissociation of personality in the dream, which, for instance, distributes one's own knowledge between two persons, one of whom, the strange one, corrects in the dream one's own ego, fully corresponds to the well-known splitting of the personality in hallucinatory paranoia; the dreamer, too, hears his own thoughts expressed by strange voices. "Even the constant delusions find their analogy in the stereotyped recurring pathological dreams. "After recovering from a delirium, patients not infrequently declare that the disease appeared to them like an uncomfortable dream; indeed, they inform us that occasionally, even during the course of their sickness, they have felt that they were only dreaming, just as it frequently happens in the sleeping dreams." CHAPTER XVI: SLEEPLESSNESS I have given in the previous chapters many reasons why human beings are compelled to seek at regular intervals an escape from reality which is made possible by the unconsciousness of sleep. Why is it then, that many people suffer from insomnia? Many physical factors are generally mentioned as the direct causes of sleep disturbances. None of them should be dismissed as unimportant; nor should any one of them, however, be accepted as an exclusive and all-sufficient explanation of sleeplessness. Coffee, tea and cocoa (the latter even in the shape of chocolate candy) taken in large quantities, particularly before retiring, affect our sympathetic or safety nerves. They make us, therefore, more sensitive to slight sound, light, pressure, smell, etc., stimuli, which under ordinary circumstances we would not notice consciously. In other words, they create imaginary "emergencies" which require the usual preparation for fight or flight, that is, keen observation of our environment, arterial tension, etc., all conditions which make sleep impossible. Yet we cannot say that coffee, tea or cocoa, without some other contributing cause would always bring about sleep disturbances. Bleuler writes: "I had been in the habit of drinking every night several cups of very strong tea which never prevented me from sleeping. Since I have had the influenza, things have been very different. I must be careful not to partake of such stimulants before going to bed. But even then, their effect depends on my mental condition. They affect me more at certain times than they do at others. If I am the least bit excited their effect is increased. When I am perfectly relaxed, I may not feel any bad effects."