Without exaggeration, it can be argued that 98% of people on earth have ever encountered a manifestation of such a thing as déjà vu. What is it and how does it manifest itself? Scientists have no consensus at the moment.
Literally deja vu is French for “already seen”
That is, a person participating in an event is firmly convinced that this has already happened to him in the past. Most often recall the common parts without small details. Perhaps even the actions are repeated, but the participants are different. Sometimes it seems that you are watching from the outside. Many experts tried to concretize how the phenomenon of deja vu occurs, but so far they have not advanced much.
Most agree: deja vu occurs as a result of some not fully understood processes in the human brain. The memory of man is huge. Over a lifetime, an enormous amount of information, events, experiences, emotions, watched films, books, fantasies accumulates. Some are intertwined with others, and what is happening in reality may seem to have once come true.
Another hypothesis is that the brain, on the basis of already available information, independently models different situations, showing them to a person during sleep, because only 10% of dreams are remembered, and the rest either remain in the subconscious or are completely forgotten. When something comparable to a dream occurs, it seems that the event has already happened.
Some consider the appearance of a déjà vu consequence of the difference in speeds between the visual perception of information and its processing in memory. That is, we are only trying to comprehend the visible, and the brain is already signaling that it is familiar to him.
Déjà vu can be a memory that manifests itself in the present. For clarity, remember the classic Soviet cinema “The Adventures of Shurik.” The student was preparing for the exam so enthusiastically that he did not even pay attention to an unfamiliar girl, not to mention the situation in her apartment. The brain subconsciously wrote down this information and “hid”, as a computer file, in a distant cell. Once again acquainted with this girl, Shurik began to show extrasensory abilities, as if he could foresee where everything was. In fact, these were real memories.
The most difficult to test hypotheses today are explanations of deja vu as links with parallel worlds, memories from past life, time travel, and other.