IT ALREADY I HAVE LIVED IT BEFORE...

When we are surprised for having attended a conversation, instant, succession of facts or another action that it sounds us very familiar like if we had lived before, this effect is named Dèja vu.

Dejà vu is a phenomenon that happens to us in certains moments in the shape of strong sensation of lived experience. It usually happen in the shape of dream or past recollection but actually this moment is totally new.

In formal studies, 70 % or more of the population affirm to have felt it at least once.

The scientific explanation is very clear: it's fault of the memory. In this effect intervene two types of memory: the short-term memory which is the one that perceives the events that belong to the present, and the long-term memory which is the one that perceives the events that belong to the past.
For example our brain, when any moment passes, has to attend the passed instants (present) and stores it in some empty place of our memory and in this way we can remember it (past), this way of consecutive form.

Our memory with dèja vu effect is when there takes place an anomaly, these actions are altering , proceeding to guard one action, instant, fact... more than one time. As this recollection already exists, gives us the familiar of already having lived it previously.