Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: I feel like I've seen this video before… Subscribe: Twitter: @okaytobesmart ↓ More info and sources below ↓ Follow on Twitter: Follow on Tumblr: Follow on Instagram: Most of us have felt it before, that strange sensation that you've been somewhere or seen something before, as if you already remembered what's happening. Are you psychic? Nope, that's just déjà vu. Why does déjà vu happen? Well, scientists aren't completely sure, but they've got a few good theories about it. Great déjà vu explainer from Jordan Gaines Lewis: Some theories of why déjà vu happens: And now for something completely different: Special thanks to Austin's Corona Cafe! Cast: Waiter - Joe Nicolosi (he's also the director) Sneezing girl - Kate Eads (she's also associate producer) Guy spilling coffee - John Knudesn (he's also gaffer) Have an idea for an episode or an amazing science question you want answered? Leave a comment below! ----------------- It's Okay To Be Smart is written and hosted by Joe Hanson, me on Twitter: @jtotheizzoe Email me: itsokaytobesmart AT gmail DOT com Facebook: Google+ +itsokaytobesmart For more awesome science, check out: Produced for PBS Digital Studios Joe Hanson - Creator/Host/Writer Joe Nicolosi - Director Amanda Fox - Producer, Spotzen IncKate Eads - Associate Producer Andrew Matthews - Editing/Motion Graphics Katie Graham - Director of Photography John Knudsen - Gaffer Dalton Allen - Post-Production Intern Theme music: "Ouroboros" by Kevin MacLeod Other music via APM Stock images from Shutterstock ----------------- Last week's video: 5 Weird Involuntary Behaviors Explained: More videos: Why Are Some People Left-Handed? Why Did We Blow on NES Games? The Science of Game of Thrones - There Was No First Human - How The Elements Got Their Names -