In most cases, however, illusions of memory growing out of previous activities of the imagination appear only after the lapse of some time, when in the natural course of things the mental images derived from actual experience would sink to a certain degree of faintness.  Habitual novel-readers often catch themselves mistaking the echo of some passage in a good story for the trace left by an actual event.  A person’s name, a striking saying, and even an event itself, when we first come across it or experience it, may for a moment seem familiar to us, and to recall some past like impression, if it only happens to resemble something in the works of a favourite novelist.  And so, too, any recital of another’s experience, whether oral or literary, if it deeply interests us and awakens a specially vivid imagination of the events described, may easily become the starting-point of an illusory recollection.

Children are in the habit of “drinking in” with their vigorous and eager imaginations what is told them and read to them, and hence they are specially likely to fall into this kind of error.  Not only so:  when they grow up and their early recollections lose their definiteness, becoming a few fragments saved from a lost past, it must pretty certainly happen that if any ideas derived from these recitals are preserved, they will simulate the form of memories.  Thus, I have often caught myself for a moment under the sway of the illusion that I actually visited the Exhibition of 1851, the reason being that I am able to recall the descriptions given to me of it by my friends, and the excitement attending their journey to London on the occasion.  It is to be added that repetition of the act of imagination will tend still further to deepen the subsequent feeling that we are recollecting something.  As Hartley well observes, a man, by repeating a story, easily comes to suppose that he remembers it.[130]

Here, then, we have another source of error that we must take into account in judging of the authenticity of an autobiographical narration of the events of childhood.  The more imaginative the writer, the greater the risk of illusion from this source as well as from that of dream-fancies.  It is highly probable, indeed, that in such full and explicit records of very early life as those given by Rousseau, by Goethe, or by De Quincey, some part of the quasi-narrative is based on mental images which come floating down the stream of time, not from the substantial world of the writer’s personal experience, but from the airy region of dream-land or of waking fancy.

It is to be added that even when the quasi-recollection does answer to a real event of childish history, it may still be an illusion.  The fact that others, in narrating events to us, are able to awaken imaginations that afterwards appear as past realities, suggests that much of our supposed early recollection owes its existence to what our parents and friends have from time to time told us respecting the first stages of our history.[131] We see, then, how much uncertainty attaches to all autobiographical description of very early life.