On the weekend, my friend the Tall Teacher (age 31) was over. He pointed to an old stereo I have and said "what's that?" In his defense it was buried under other things, hoarder-style.
I said it's an old stereo. It was my father's. I kept it because it was the only one we had that played 78's.
He asked (you guessed it) "What are 78's?"
I said 78 rpm records. Vinyl. And I showed him one. He'd never heard of 78's. I showed him a couple. Very heavy vinyl, bigger than an 45, one song per side. He said: one song only? That's not very environmentally friendly.
I love that. Who thought about the "environment" in the days of 78's?