If you are referring to a hook as in the attention grabbing part in a story, one that could apply for “How we remember the past” could be: Memories, joyful, sad, wild and adventurous. But why is it that we have them, how exactly do we remember our past events?
If this was not what you were looking for I apologize ❤️
I would say an unreliable narrator because that kind of narrator is the best at keeping secrets from the reader. If that's not an option, then a restricted narrator because they only know a limited amount of information.