Once the sleeping state overcome, the censorship resumes complete sway, and is now able to revoke that which was granted in a moment of weakness. That the _forgetting_ of dreams explains this in part, at least, we are convinced by our experience, confirmed again and again. During the relation of a dream, or during analysis of one, it not infrequently happens that some fragment of the dream is suddenly forgotten. This fragment so forgotten invariably contains the best and readiest approach to an understanding of the dream. Probably that is why it sinks into oblivion—_i.e._, into a renewed suppression. XI. Viewing the dream content as the representation of a realised desire, and referring its vagueness to the changes made by the censor in the repressed matter, it is no longer difficult to grasp the function of dreams. In fundamental contrast with those saws which assume that sleep is disturbed by dreams, we hold the _dream as the guardian of sleep_. So far as children’s dreams are concerned, our view should find ready acceptance. The sleeping state or the psychical change to sleep, whatsoever it be, is brought about by the child being sent to sleep or compelled thereto by fatigue, only assisted by the removal of all stimuli which might open other objects to the psychical apparatus. The means which serve to keep external stimuli distant are known; but what are the means we can employ to depress the internal psychical stimuli which frustrate sleep? Look at a mother getting her child to sleep. The child is full of beseeching; he wants another kiss; he wants to play yet awhile. His requirements are in part met, in part drastically put off till the following day. Clearly these desires and needs, which agitate him, are hindrances to sleep. Everyone knows the charming story of the bad boy (Baldwin Groller’s) who awoke at night bellowing out, “_I want the rhinoceros_.” A really good boy, instead of bellowing, would have _dreamt_ that he was playing with the rhinoceros. Because the dream which realises his desire is believed during sleep, it removes the desire and makes sleep possible. It cannot be denied that this belief accords with the dream image, because it is arrayed in the psychical appearance of probability; the child is without the capacity which it will acquire later to distinguish hallucinations or phantasies from reality.