Why do we shake hands? It may seem ordinary now, but this age-old greeting has roots in ancient peacekeeping. Thousands of years ago, extending your right hand was a way to show you weren’t armed—no dagger, no threat. It was basically the original “I come in peace.”

The shake part? Historians think it helped dislodge any hidden weapons or showed you were serious about a deal—like saying, “I mean it,” with a firm grip. Even Greek gods and warriors were depicted doing it. A simple gesture with a surprisingly sharp backstory.