It is strange and unsettling, leaving a person feeling confused and puzzled. It could be a sound, a sentence spoken or a place visited that leaves people feeling like they have been in the same situation before or even having felt the same kind of emotion at a particular situation before.

Déjà vu, a French term literally means, “already seen”. But jog down the memory lane and one can’t remember ever having been to that place before, even though there is this eerie feeling of familiarity with a current situation.

To make it simpler, though it is a highly complicated thing to understand, you are visiting a famous building or any new place, suddenly you feel like you have been in the exact spot before even though you haven’t.

Or even when one is in a certain situation with a group of friends or family, and someone utters a sentence; it feels like one has heard the same kind of sentence in the same group before at the same place. It is a fleeting feeling, and leaves one wondering what is happening?

The easiest answer that comes to mind for this complex phenomenon is that one has had a past life and has thus been in the same situation or seen the same place before and somewhere in the memory bank, this leftover piece from a long forgotten experience has resurfaced. And surprisingly, quite a few people, even researchers are happy with the explanation. But déjà vu is much more intricate to understand than that.

According to a Swiss Scholar Arthur Funkhouser, one has to first categorise the feeling to better understand it. The experience of having visited the same place before is termed ‘deja visite’ meaning already visited and the second is ‘deja vecu’ which means already felt or experienced. And do not be surprised if you have ever felt this way or will feel this way in future as it has been estimated that 70 per cent of individuals have had this feeling sometime in their lives.

Why this occurs is also a bit vague but psychoanalysts and researchers are continuing to research this feeling and so far the answers we do have in some way help us understand why it happens. Speaking scientifically, people suffering from epilepsy seizures have this feeling if they are suffering from a disorder called ‘temporal lobe epilepsy’ and have this feeling during or between convulsions. But normal people with no psychological disorder also go through this feeling and here is where the mystery and myth begin. Serious researchers too try to explain but they can only speculate and offer the best explanation that they can.

First of all, having a past life is not the only answer. Some say that it could be due to a person having heard or read about a certain place before and forgotten about it only for the memory to have come back again when the individual actually did go to the place. In the same way, a familiar situation could be the result of having read about certain sentence spoken at a certain time. To be more scientific, it is said that one part of the brain receives signals just a tiny mini-second before the second part. So when both parts of the brain actually gather the information one has the feeling that the earlier information received is a faint memory.

But then there are some who debate that there is no neurological cause. The mysterious feeling could be because — and hold your breath for this one — there have been many Big Bangs when the entire universe has been created and recreated. So in some other universe we might have experienced it. But this would mean being reincarnated in the same universe. If you think this is crazy, what could be the reason say researchers for another mystery?

Hyper perception? Now this, dear friends, has nothing to do with the accepted or regular theories of déjà vu.

In hyper perception, the feeling of familiarity is not just fleeting and it grows the longer one stays in a place. For example, tour guides often state that while showing visitors a certain monument or building, people have come up to them and asked if the floor had been redone as it had been different or the garden had a certain tree at a certain spot before, which it actually did have, maybe centuries before. Could it be some sort of genetic link to the family that owned the place, so that somewhere from the deep crevices of the mind, an old memory of a long dead ancestor cropped up? Maybe and maybe not. You tell me.