Although it sounds similar to the word “amnesia,” “anamnesis” has a different meaning, which is reflected in the words’ opposite roots. “Amnesia,” the term for a partial or total loss of memory, comes from the Greek “amnēsia,” meaning “forgetfulness.” “Anamnesis,” meanwhile, derives from the Greek “anamnēsis,” which adds a prefix to give the opposite meaning, “remembrance.” Experiencing déjà vu — the intense feeling of having experienced something before — is sometimes attributed to anamnesis, but it likely has a more practical explanation. Researchers believe déjà vu can generally be attributed to one of a few different explanations: a minor brain “glitch” wherein short-term memories are confused with long-term memories, a memory that someone doesn’t properly recall, or a dream or other subconscious experience.