In fact, from a scientific point of view, there is still so much we don't understand about the nature of memory. What is not debated is how important memories are to us and how influential they can be on us. They define a person and constitute their individuality. The idea of manipulating our memories or having them stolen away from us feels... heinous.
Perhaps the strangest and most precious gift of memory is when you rediscover something you haven't thought about in so long. A time, a place, a feeling, a sense, a being. Sometimes they're sad, sometimes their joyous, but each contributes to the person you are now. Let's do a writing exorcise: Write down as many things as you can starting with "I remember..." in 5 minutes. It's good to revisit old memories, to appreciate them, to cherish them, and to understand a little bit more about yourself.