Here's a deep dive into déjà vu. Many people have experienced the uncanny feeling of a brand new situation seeming very familiar — what is going on here? Why does it happen?

Experts explain what déjà vu is, why it happens, what it feels like, and when it could indicate a serious medical condition.

Déjà vu is the eerie feeling that you have had the same novel experience before. It’s a spontaneous, elusive sensation that reveals the workings of consciousness, ...