Déjà vu is a French term describing the feeling that one has lived through the present situation before. Déjà vu is a feeling of familiarity and déjà vécu (the feeling of having "already lived through" something) is a feeling of recollection. Scientific approaches reject the explanation of déjà vu as "precognition" or "prophecy," but rather explain it as an anomaly of memory, since despite the strong sense of recollection, the time, place, and practical context of the "previous" experience are uncertain or believed to be impossible. Two types of déjà vu are recognized: the pathological déjà vu usually associated with epilepsy or that, when unusually prolonged or frequent, or associated with other symptoms such as hallucinations, may be an indicator of neurological or psychiatric illness,and the non-pathological type characteristic of healthy people, about two-thirds of whom have had déjà vu experiences