We forget the greater part of the occurrences of the years and days of this life, but no one would say for that reason we did not go through these years. They were lived, and we retain but little of the details in the brain, but the entire effect of them on the character is kept and made a part of ourselves. The whole mass of detail of a life is preserved in the inner man to be one day fully brought back to the conscious memory in some other life when we are perfected. And even now, imperfect as we are and little as we know, the experiments in hypnotism show that all the smallest details are registered in what is for the present known as the sub-conscious mind. The theosophical doctrine is that not a single one of these happenings is forgotten in fact, and at the end of life when the eyes are closed and those about say we are dead every thought and circumstance of life flash vividly into and across the mind.
Many persons do, however, remember that they have lived before.
Poets have sung of this, children know it well, until the constant living in an atmosphere of unbelief drives the recollection from their minds for the present, but all are subject to the limitations imposed upon the Ego by the new brain in each life. This is why we are not able to keep the pictures of the past, whether of this life or the preceding ones. The brain is the instrument for the memory of the soul, and, being new in each life with but a certain capacity, the Ego is only able to use it for the new life up to its capacity. That capacity will be fully availed of or the contrary, just according to the Ego's own desire and prior conduct, because such past living will have increased or diminished its power to overcome the forces of material existence. But as the brain had no part in the life last lived, it is in general unable to remember.