it's mesmerizing thinking of how our brain fools us into believing we were in this situation before. About “déjà vu” and I learnt lots about it. Déjà vu is a peculiar sensation in which a scenario feels much more familiar than it should. Young individuals are the ones that have the most déjà vu. There is no solid data as to how common it is, but estimates imply that it affects somewhere between 60 and 80 percent of the population, a familiar sight or sound can trigger the feeling. You may walk into a room in a building you've never visited yet feel like you know it intimately.