Chances are, we will encounter our own double–or doppelganger–in our lifetime. But do we really share exact facial features with others? “Science tells us that, technically, doppelgangers don’t exist,” says Joe Hanson, host of It’s Okay To Be Smart. “Every face that’s ever been is unique. But science also tells us that we are really good at fooling ourselves.” He explains further in this fascinating episode.