The full force of this circumstance is best seen in the fact that a very recent event, bringing with it a deep mental shock and a rapid stirring of wide tracts of feeling and thought, may get to look old in a marvellously short space of time. An announcement of the loss of a dear friend, when sudden and deeply agitating, will seem remote even after an hour of such intense emotional experience. And the same twofold consideration probably explains the well-known fact that a year seems much shorter to the adult than to the child. The novel and comparatively exciting impressions of childhood tend to fill out time in retrospect, and also to throw back remote events into a dimly discernible region. Now, this same circumstance, the degree of vividness or of faintness of the mnemonic image, is that which determines our idea of distance when the character of the intervening experiences produces no appreciable effect.[124] This is most strikingly illustrated in those imperfect kinds of recollection in which we are unable to definitely localize the mnemonic image. To the consideration of these we will now turn. B. _Indefinite Localization._ Speaking roughly and generally, we may say that the vividness of an image of memory decreases in proportion as the distance of the event increases. And this is the rule which we unconsciously apply in determining distance in time. Nevertheless, this rule gives us by no means an infallible criterion of distance. The very fact that different people so often dispute about the dates and the order of past events experienced in common, shows pretty plainly that images of the same age tend to arise in the mind with very unequal degrees of vividness. Sometimes pictures of very remote incidents may suddenly present themselves to our minds with a singular degree of brightness and force. And when this is the case, there is a disposition to think of them as near. If the relations of the event to other events preceding and succeeding it are not remembered, this momentary illusion will persist. We have all heard persons exclaim, "It seems only yesterday," under the sense of nearness which accompanies a recollection of a remote event when vividly excited. The most familiar instance of such lively reproduction is the feeling which we experience on revisiting the scene of some memorable event. At such a time the past may return with something of the insistence of a present perceived reality. In passing from place to place, in talking with others, and in reading, we are liable to the sudden return by hidden paths of association of images of incidents that had long seemed forgotten, and when they thus start up fresh and vigorous, away from their proper surroundings, they invariably induce a feeling of the propinquity of the events.