Why do we sometimes experience the strange feeling of déjà vu?

We sometimes feel like we’ve already been somewhere or done something before, even when we haven’t, that’s déjà vu.

Imagine you're playing with your favorite building blocks. You stack them in a certain way, and suddenly it feels just like the time you built that same tower last week. But you didn’t remember doing it before! That strange feeling is déjà vu.

Think of déjà vu like hearing a song you’ve heard before but can't quite place. Your brain thinks, “I know this!” even if your body doesn’t remember exactly when or where you heard it.

Sometimes, your brain gets a little ahead of itself, like when you're walking into the kitchen and suddenly realize you’re going to get a cookie. You feel like you’ve done that before because your brain remembered part of the story but not all of it.

It's kind of like when you see something familiar in a new place, your brain goes, “Hey, I know this!” even if you can’t remember exactly why.