I have never heard that expression in my entire life. Wow.
It happens. It's amazing sometimes that you can go your entire life without knowing what many consider to be common knowledge. Last year someone was at my house helping made a dinner for some friends and asked for a ramekin. I had no idea that a small bowl was called a ramekin but everyone else said that was common knowledge that everyone knew.
I've no idea how I managed to go my entire life never knowing that.