Imagine this: You’re walking down the street, making your way home after a night out with friends. One friend makes a comment, another responds, and you perk up your ears—you’ve heard this exact conversation before. In fact, even though you’re in a neighborhood that’s new to you, everything from the streetlights to the bustle of traffic to the animated chatter of your friends feels deeply familiar. It’s as though you’re looping back to a moment that’s already been logged in your memory, even though that can’t possibly be the case. You may have even paused and marveled at the creepy phenomenon: “Whoa! Deja vu.”