I stared down at the ruler thinking and probably said out loud, "Which ones millimeter?" I yelled for my husband and asked him. He was just as clueless as I was. We both drew our weapons of mass destruction out, our iPhones, and clicked on a measuring app. We came to the conclusion that one inch was exactly 25.4 millimeters, which of course I knew all along. He dug out before I could burden him with more jewelry talk.
"Why in the world am I going to need to know this when I'm an adult?"Anddd..... now I know. Duh.