Everyone has felt many times in his life a sense of familiarity with incidents that have had no place in his own experience, and has found it impossible to offer any explanation for the feeling. Coming suddenly around a turn of a hill upon a fair and unknown landscape, his heart may bound with a keen sense of recognition of its unfamiliar outlines. In the midst of a tingling scene of emotion, a sensation of the whole incident being a mere dull repetition will rob it of its joy or pain. A sentence begun by a friend is recognized as trite and old before it is half done, though it refers to matters new to the hearer. A sound, a perfume, a sensation, will awaken feelings having no connection with the occasion.
The first day I ever spent in a tropical country I was charmed with the excessive novelty of everything about me; but suddenly that evening, being carried home in a chair by the coolie bearers, a flood of recognition poured over me like the waves of the sea, and for a few minutes the illusion was so strong as to leave me breathless with astonishment. I had the sense of having often done this before. The warm night, the padding of the bare feet in the dust, the hot smell of leaves, were all an old, trite experience. For days I struggled with that tormenting sense, with which we are all familiar, of being unable to recall a something, a name, that is perfectly well known--is "on the tip of the tongue," as one says--but all in vain; and in time the recognition grew fainter and more elusive with each effort to grasp it, until it slipped forever away into darkness. If such experiences as these are not inherited memories, what are they?
With sleep, the will becomes dormant. Waking, it guards and governs; chooses what we shall do and be and think; stands sentinel over the mind and rejects all comers with which it is not familiar. Unless the thought comes from within the known borders of the body's own life, the will will have none of it. But overtaken by fatigue and sinking into slumber with the night, his domain is left fenceless and unpatrolled, for with the will goes his troop of watchmen, judgment, logic, deliberation, ethics; and memory, ungoverned and uncontrolled, holds a feast of misrule. The barrier between past and present melts away; all his ancestors are merged into the individual; the events of the day are inextricably tangled with those of two centuries since, and this motley play of time is called a dream.