The multiverse is a hypothetical group of multiple universes. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, information, and the physical laws and constants that describe them.
Tabula rasa is the theory that individuals are born without built-in mental content, and, therefore all knowledge comes from experience or perception. Epistemological proponents of tabula rasa disagree with the doctrine of innatism which holds that the mind is born already in possession of certain knowledge.
The term déjà vu is French and means, literally, “already seen.” Those who have experienced the feeling describe it as an overwhelming sense of familiarity with something that shouldn’t be familiar at all. Say, for example, you are traveling to England for the first time. You are touring a cathedral, and suddenly it seems as if you have been in that very spot before. Or maybe you are having dinner with a group of friends, discussing some current political topic, and you have the feeling that you’ve already experienced this very thing — same friends, same dinner, same topic.