What is the nature of human memory?
The ambiguity of this query opens up the field for off-the-wall answers, so here goes. "Human Memory" is possibly taken two ways, either the collective memory of the human race, or the memory of individual humans. Within these, as well, the possible meanings multiply. The physical mechanics? The philosophical meanings? The social implications? The genetics? As we delve, we are overwhelmed with uncertainty. A great wave of doubt and confusion overcomes the mind.
The flattened wreckage, as by some hurricane, is left, barren. From this comes the remnant of mind, untouched by the onslaught of reason gone horribly wrong, rising above the destruction that surrounds. This is the memory. The collective memory of a day gone by. A day of peace and contentment. Paradise, lost. Utopia, fallen. Perfection, corrupted. This is an idea common to all our little world; one which appears in all human cultures. A time and/or place of bliss.
This is a memory that finds itself manifested in the Mosaic writings (Torah/Pentatuach) as the Gan Eden (Garden of Eden). It is a perfection dreamed of in the romanticized utopias of the 19th century, and one mocked in the dystopias of the 20th. A perfection for which we, as imperfect specimens, human, strive; a purpose in a societal struggle. This memory may or may not have ever had a root in actual events, yet its driving force is not derived from actuality, but from potential good. The idea instills a sense of potency into the frail human soul, a reason to try.
The human need for a reason to live sprang up religion; that hierarchy where humans are no longer supreme, but must answer to a higher, judging, being. The idea that there is a greater one, expecting improvements, discourages the species from being satisfied with merely taking life and the world as it comes, but rather to improve. The older sibling expecting you to do it, and encourages you on the way, is an idea that forms the basis of many deities. These deities become surrounded in more stories and myths, fleshing out hopes into "facts".
Thus the paradise illusion/memory/myth common to much of humanity created an idea which has managed to drive countless wars, treaties, and treatises.
The cultural memory is passed on generation to generation (l'dor va'dor); from mother to child. In the folk tales of princes and dragons and witches and goblins, we instill the ideas and memories of a people gone, yet still carried on into the present, and, ultimately, the future.