evidence for precognition has been put forward, both as witnessed anecdotes and as experimental results, but none has been accepted as rigorous scientific proof of the phenomenon. Even the most prominent pieces of evidence have been repeatedly rejected due to errors in those experiments as well as follow-on studies contradicting the original evidence. This suggests that the evidence was not valid in the first place. Alternative explanations Various known psychological processes have been put forward to explain experiences of apparent precognition. These include: Coincidence, where apparent instances of precognition in fact arise from the law of large numbers.Sutherland, Stuart. (1994). Irrationality: The Enemy Within. pp. 312–313. Penguin Books. Self-fulfilling prophecy and unconscious enactment, where people unconsciously bring about events which they have previously imagined. Unconscious perception, where people unconsciously infer, from data they have unconsciously learned, that a certain event will probably happen in a certain context. When the event occurs, the former knowledge appears to have been acquired without the aid of recognised channels of information. Retrofitting, which involves the false interpretation of a past record of a dream or vision, in order to match it to a recent event. Retrofitting provides an explanation for the supposed accuracy of Nostradamus's vague predictions. For example, quatrain I:60 states "A ruler born near Italy...He's less a prince than a butcher." The phrase "near Italy" can be construed as covering a very broad range of geography, while no details are provided by Nostradamus regarding the era when this ruler will live. Because of this vagueness, and the flexibility of retrofitting, this quatrain has been interpreted by some as referring to Napoleon, but by others as referring to the Holy Roman Emperor Ferdinand II, and by others still as a reference to Hitler. False memories, such as Identifying paramnesia and Memory biases, where the memory of a non-existent precognitive event is formed after the real event has occurred. Where subjects in a dream experiment have been asked to write down their dreams in a diary, this can prevent selective memory effects such that the dreams no longer seem accurate about the future. Déjà vu, where people experience a false feeling that an identical event has occurred previously. Some recent authors have suggested that déjà vu and identifying paramnesia are the same thing. This view is not universally held, with others instead treating them as distinct phenomena. Psychological explanations have also been proposed for