Have you ever walked into a room or heard someone say something and got a strange feeling that moment had happened before? That weird, eerie feeling is called deja vu, and it is actually quite common and happens to many individuals.
Deja vu means “already seen” in French, which is why it describes when we feel like we have experienced something before, even though we definitely have not. 60 to 80 percent of the population have experienced it many times and 97 percent of the population has experienced it at least once. Furthermore, it tends to happen more in teenagers and young adults as their brains are still fully developing. It can also be more common in people who have a higher level of education, remember their dreams consistently, or traveled to many places.
Deja vu is still not fully understood by scientists, and research about it is still being continued. However, the basic explanation for how it is thought to happen is a misfire of your brain. To explain this further, there is a miscommunication between the parts of the brain involved in the process. This includes the hippocampus, which is in charge of taking in new information, and the temporal lobe, which is in charge of memory. Memories and new surroundings can tangle in the brain while being processed, causing false memories, or deja vu.
Another and more detailed way of explaining this process is that the hippocampus usually stores that piece of new information as a short term memory. However, a small miscommunication may happen, causing it to store the experience as a long term memory instead. This can cause something brand new to feel like it has already happened before.
Deja vu can even be a symptom of different health conditions. People who have frontotemporal dementia or epilepsy can get deja vu due to misfires in the temporal lobe. Another health condition that can cause deja vu is sleep deprivation; the brain gets disrupted if there is a lack of sleep, which can cause miscommunication. Lastly, deja vu can happen to people with stress and even anxiety since the brain can twist the information they are processing as a coping mechanism during stress. Even though deja vu can be a result of all of these, it is still a common occurrence for people without any conditions, as long as it is not extremely frequent or long-lasting.
There are even other variations of deja vu, like deja reve. Deja reve is French for “already dreamed” and is the feeling that something that you are experiencing has already happened in a dream. Although this is not as common as deja vu, it is very similar and many still experience it.
A small malfunction like deja vu can remind us how powerful the brain really is. Caused by just a small delay in brain signals, it can still make you stop and wonder. Next time you experience deja vu, instead of panicking, just remember how you experienced one of the brain’s strangest mysteries.
Works Cited:
Cleveland Clinic. (2025, June 17). Why you get déjà vu. https://health.clevelandclinic.org/deja-vu-what-it-is-and-when-it-may-be-cause-for-concern
Heyl, J. C. (2024, September 17). Wait, I’ve dreamt about this before-it’s not Deja Vu, it’s Deja Reve. Verywell Mind. https://www.verywellmind.com/deja-reve-8704831
Pappas, S. (2024, February 20). What causes Déjà Vu?. Scientific American. https://www.scientificamerican.com/article/what-causes-the-feeling-of-deja-vu/
Raypole, C. (2020, March 30). What causes Déjà Vu?. Healthline. https://www.healthline.com/health/mental-health/what-causes-deja-vu#what-it-is
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