Explain why déjà vu, despite its name and its association with memory, is not classified as a true memory disorder.

A true memory disorder involves some actual failure or distortion of stored, previously encountered material. In déjà vu, there is no prior experience of the situation at all — nothing has actually been forgotten, distorted, or wrongly recalled. What's disturbed is purely the felt sense of familiarity that normally accompanies genuine recognition; that feeling is misfiring and attaching itself to a brand-new experience. Because nothing about the person's actual memory content is wrong, it's classified as a disturbance of familiarity rather than a disorder of memory itself.