Déjà Vu is a feeling of sensation when one person feels that they have felt or witnessed the same situation before, just like a single incident is happening once again. The word itself is from French and means "already seen." Though there is a common misconception among people that Déjà Vu is a very rare occurrence, in reality, this apparently mysterious experience happens to almost 97 percent of people's lives. Thus, it is a very common thing that will be felt by most people at least once in their lifetime.What Is Déjà Vu?As mentioned before, the word itself shows the very aspect of Déjà Vu that it's already seen. Suppose you are having a deep conversation with your friend, family, or a stranger, but you feel like this is not the first time you are having this conversation; you already know the topics and outcomes, as if you are living the same moment that you have lived before.On the other hand, you might be visiting a new place, maybe a new city that you have never visited, but the places, houses, and overall atmosphere feel very recognizable. You suddenly feel that you have visited that place before and have felt good or bad in the past, as if you are living a past in your present.All in all, this kind of strange phenomenon that happens to people regularly, this kind of uncomfortable feeling which is felt by 97 percent of people in the world, is called Déjà Vu.What Causes Déjà Vu?The root cause of this strange phenomenon is believed to be a result that one place or any conversation or any situation is resembling the same kind of pattern or feelings that you have experienced and felt before, and in most cases, you yourself have forgotten that, but your brain has not, and it recreates this sense of familiarity, and you feel you are living in a paradox.In other words, déjà vu occurs when two parts of your brain fail to communicate properly: the temporal lobe, which handles memories, and the hippocampus, which processes new experiences.Also Read: 7 Minutes Of Life: The Science Behind What Happens To Your Brain After You Die What Is The Connection Between Health Conditions And Déjà Vu?There are certain things that can cause Déjà Vu more than others, such as fatigue or sleep deprivation, stress, and anxiety, which can trigger the feeling of Déjà Vu, as this pressure on your mental and physical health might pressure your brain and distort the recognition process. Other than that, migraine, dementia, and seizure can also cause Déjà Vu in a person.Occasional déjà vu is generally harmless and not a cause for concern. However, if it happens frequently, lasts more than a few seconds, or is accompanied by other symptoms, it may be a good idea to seek medical advice.