What Is Deja Vu and Why Do We Experience It?

What Is Deja Vu?

What Is Deja Vu?

We would be shocked if you’ve never experienced deja vu before. You know, the knowledge that this is the first time you’ve ever done something–but yet you just feel like you’ve done it before. Sometimes it’s strong enough to make you stop doing whatever it is you’re doing. But besides being a glitch in the Matrix, what is deja vu, and do we know why we get it?

In case you were wondering, since deja vu (déjà vu) clearly isn’t English, it’s French for “already seen.”

Deja Vu Statistics

Deja vu is pretty much a medical mystery, though that doesn’t mean we know absolutely nothing about it. Unfortunately, for the study of the subject, there’s no button we can press that’ll make it happen. It either happens or it doesn’t, and if you’re experiencing it–it largely feels random. Most of the time anyway. Hypnosis has been anecdotally said to cause deja vu, but that’s a whole can of worms. 

Anyway, over 60% of people experience deja vu, and its onset appears to begin somewhere between ages 8 and 9. There’s a peak during adolescence and early adulthood before instances taper off over time. Thus, there are quite a few proponents of linking deja vu and the development of the brain.


So here’s the thing about deja vu, so many people experience it that it’s hard to pin down concrete causes. That’s why a lot of people attribute it to glitches in the Matrix. Outside of the realm of research, it’s also why deja vu is very significant to many religious and spiritual beliefs. Deja vu and its variants have historically been seen as prophetic visions from a deity or visions from a past life. 

Contemporary research has been able to localize deja vu with the temporal lobe. It serves an important role in encoding long-term memories, as well as processing things you hear and see. Furthermore, research has linked deja vu to temporal epilepsy, since it’s generally considered a misfire in the brain. Very frequent deja vu is often associated with damage to the temporal lobe. 

This is why frequent and intense instances of deja vu are often considered cause to go to a doctor. Especially since some people experience minor “partial seizures” with these feelings. If you don’t know what that’s like at all, the feeling of falling when you’re in bed is a good example. 

It’s Not All Bad

Though, less alarmingly, deja vu may also be the result of a failure to properly encode long term memories. Maybe you saw something and it never really stuck in your mind. Later you see it again, but you don’t really remember having seen it the first time. Your experiences and memories thus come into conflict. Memories also decay over time, recalling something is like photocopying it over and over again each time you recall the memory. It turns remembering into a literal telephone game. So a given memory could have just decayed enough to be effectively forgotten, and now you’re seeing something that elicits that experience again. 

It’s probably why we don’t experience deja vu for the first time until we are older–we don’t have any memories to mentally glitch out with. The memory bug theory is also aided by the simple fact that we don’t remember much of our childhoods–despite experiencing things as kids. 

Some research suggests deja vu is simply a product of how the brain is wired. Since you don’t really get new brain cells, the brain essentially has to make do with the resources it’s given from the get go–while also making do with the fact that those resources will reduce over time. As a result, the brain tries to find the most efficient ways to encode your memories and skills. Sometimes the wires just get… crossed. 

Deja Vu Variants

It probably doesn’t surprise you to read that deja vu has its variations that make things a little more specific. 

  • Deja Vecu–“Already Living Through”
  • Presque Vu–“Almost Seen”
  • Deja Reve–“Already Dreamed”
  • Deja Entendu–“Already Heard”

Most of these are pretty self explanatory. They’re just breakdowns of deja vu for different senses. Deja reve is about feeling like something you dreamed is happening right now though, and not about feeling like you’re dreaming something you’ve dreamed before. 

Presque vu is kind of like deja vu sitting on the tip of your tongue. Not really, it’s deja vu adjacent only in that it has similar causes, is seemingly as random, and leaves similar feelings of frustration. Regardless, presque vu is the feeling of being on the edge of revelation. 

Jamais Vu

You’ve probably heard of jamais vu before, and were wondering why we didn’t lump it in with all the other deja vu variants. Really it’s just because jamais vu is the polar opposite of deja vu. It’s knowing that you’ve done something before but feeling like you’re doing it for the first time.

Linked to similar causes as deja vu, jamais vu is also linked to memory conditions like amnesia.

Weirdly enough, a study done at Leeds University was able to perhaps induce jamais vu by having participants write the word “door” a bunch. They ended up beginning to doubt it was a real word. The general conclusion was the repeated use of the word caused the brain to become so desensitized to it it just lost its meaning. 

You might be able to experience jamais vu right now! You might get it if you watch this video of every time Dwight says “Michael” from The Office. The name stops sounding right.

We’d be surprised if you’ve never experienced deja vu before. Here’s a number quiz themed around it.