Does déjà vu hint at parallel universes? Is it evidence of reincarnation from a past life? Or is it simply a curious mental error, a telltale glitch in our brain that hints at the architecture of the mind? It depends on who you ask. Déjà vu invokes a sudden sensation of familiarity, most commonly in response to a scene, but the stimulus could also be a person, place, or even just a passing thought.