A different variety of sleeplessness is that which attacks the sufferer early in the morning, say three or four hours before he wishes to get up. For this a somewhat heroic remedy may be tried, since it is always possible that natural awaking may mean one thing--namely, that you have had enough sleep. Therefore, it may be worth while, just once or twice, to try the effect, if you are really broad awake, of getting up instead of encouraging yourself to wake early again by letting this early waking dwell on your mind. You will probably be very tired by the next evening, you may even (in this case the remedy is clearly futile) be too tired to sleep. But it may easily happen that you will sleep that night exceedingly well, and wake at a normal time again. But if again, and yet again you continue to wake early, it is no use persisting in this treatment. Or you may awake, as stated before, owing to the airlessness of your room, and the fact that you have been breathing with an open mouth, or, and this is probably a frequent cause of early awakings, you may be engaged for weeks or months together on some absorbing occupation. You sleep at first because tired, and sleep deeply, but as the hours go by the sleep becomes lighter, and before your body regains consciousness at all, that strange part of the brain, the subliminal self, or the sub-conscious self, is awake, and begins thinking (gradually arousing the rest of you) of the engrossing occupation. Soon the whole brain is awake, and by the sub-conscious self is reminded, as it were, of the business. Then having once begun thinking about it, it is difficult for you to regain that passivity which is invariably the prelude to sleep, though it need be scarcely more than instantaneous.