That some instances of this puzzling sense of familiarity can be explained in this way is proved.  Thus, Paul Radestock, in the work Schlaf und Traum, already quoted, tells us:  “When I have been taking a walk, with my thoughts quite unfettered, the idea has often occurred to me that I had seen, heard, or thought of this or that thing once before, without being able to recall when, where, and in what circumstances.  This happened at the time when, with a view to the publication of the present work, I was in the habit of keeping an exact record of my dreams.  Consequently, I was able to turn to this after these impressions, and on doing so I generally found the conjecture confirmed that I had previously dreamt something like it.”  Scientific inquiry is often said to destroy all beautiful thoughts about nature and life; but while it destroys it creates.  Is it not almost a romantic idea that just as our waking life images itself in our dreams, so our dream-life may send back some of its shadowy phantoms into our prosaic every-day world, touching this with something of its own weird beauty?

Not only may dreams beget these momentary illusions of memory, they may give rise to something like permanent illusions.  If a dream serves to connect a certain idea with a place or person, and subsequent experience does not tend to correct this, we may keep the belief that we have actually witnessed the event.  And we may naturally expect that this result will occur most frequently in the case of those who habitually dream vividly, as young children.

It seems to me that many of the quaint fancies which children get into their heads about things they hear of arise in this way.  I know a person who, when a child, got the notion that when his baby-brother was weaned, he was taken up on a grassy hill and tossed about.  He had a vivid idea of having seen this curious ceremony.  He has in vain tried to get an explanation of this picturesque rendering of an incident of babyhood from his friends, and has come to the conclusion that it was the result of a dream.  If, as seems probable, children’s dreams thus give rise to subsequent illusions of memory, the fact would throw a curious light on some of the startling quasi-records of childish experience to be met with in autobiographical literature.

Odd though it may at first appear, old age is said to resemble youth in this confusion of dream-recollection with the memory of waking experience.  Dr. Carpenter[128] tells us of “a lady of advanced age who ... continually dreams about passing events, and seems entirely unable to distinguish between her dreaming and her waking experiences, narrating the former with implicit belief in them, and giving directions based on them.”  This confusion in the case of the old may possibly arise not from an increase in the intensity of the dreams, but from a decrease in the intensity of the waking impressions.  As Sir Henry Holland remarks,[129] in old age life approaches to the state of a dream.