The impressions that man acquires from his experiences fade gradually from memory. Not so, however, their fruits. We do not remember all the experiences lived through during childhood while acquiring the arts of reading and writing. Yet we could not read or write had we not had such experiences, and had not their fruits been preserved in the form of abilities. Such is the transmutation that the spirit effects in the treasures of memory. The spirit consigns to its fate whatever can lead to pictures of the separate experiences, and extracts therefrom only the force necessary for enhancing its abilities.
Thus not a single experience passes by unutilized. The soul preserves each one as memory, and from each the spirit draws forth all that can enrich its abilities and the whole content of its life. The human spirit grows through assimilated experiences, and although one cannot find past experiences in the spirit as if in a storeroom, one nevertheless finds their effects in the abilities that man has acquired.
Source: Rudolf Steiner – GA 9 – Theosophy: Chapter II. Re-embodiment of the Spirit and Destiny
Translated by Henry B. Monges and revised for this edition by Gilbert Church, Ph.D