The theories in modern science to explain this phenomenon are far from satisfactory. According to the questionnaire survey, two thirds of adults have had at least one "deja vu" experience. And the more imaginative people are, the more likely they are to experience strange feelings; People who travel frequently are more likely to feel deja vu than those who stay at home for a long time; In addition, people with higher education can feel this feeling better than others (perhaps this is because they have experienced unique feelings in Tolstoy or some literary masters). The survey also shows that the incidence of "deja vu" is the highest in youth, and then gradually decreases with age. Especially when people really start to repeat the monotonous life day after day, the incidence decreases. A century ago, when Freud's theory was the mainstream of leadership psychology research, analysts interpreted "deja vu" as the embodiment of subconscious conflict. But now psychologists have suggested that "deja vu" does not necessarily happen on the basis of deep subconscious conflicts. The average healthy brain will feel this way. Moreover, when people are tired and stressed, it is easy to feel this way. In addition, it may be accompanied by "jamaisvu", that is, when you see familiar things or words, you can't remember anything. Psychologists also point out that the feeling of deja vu may be due to people accepting too much information and not paying attention to its source. Familiarity will come from various channels, some real and some illusory. When you encounter a situation described in a novel that you have forgotten, you may regard it as a memory of your past life. In other words, when you see the real scene of the movie, although you have completely forgotten the movie on the surface, you will still recall thrilling memories in your mind. Psychologists also point out that people sometimes don't need real memories at all, and it is possible to create a familiar feeling inside the brain.