Too great a question for so small a space! Psychologists tell us that déjà vu is a quirk of memory. Memory is an essential part of what it means to be an individual. No one shares your exact memories; they make you who you essentially are! Memory is to an individual what history is to a community. It shapes our opinions and attitudes and helps us make choices. Without memory, without history, we would be lost. Déjà vu raises the question of how solid our memory is, and maybe how clear our sense of ourselves and our place in history may ultimately be.