K-Girl, I just used my fingernail.
Himself and I were just listing a lot of things that younger people won't "get". I know when I was growing up, my folks used to explain old-time expressions and actions they had when they were growing up. We've used lots of those expressions with our own kids over the years - and most of them haven't needed explaining. But neither of them have kids or look like they'll be adding to the population, so I guess any old expressions will die off with them.
Our daughter was around 4th grade, so maybe 10 years old? It was about 1993 or '94. She got to be a helper in the school office. One day one of her classmates had to use the office phone to call her Mom - the girl wasn't feeling good and needed to go home. They had a rotary dial in the office. The sick girl looked at the phone and said "how do I use it"? Since Grandma had an old rotary phone at home, our daughter got to show her.