I was just clearing the theater after a show, and a kid who had been in the audience says to me, “My favorite part was where the guy threw the disc-thing and hit the king in the head.”*
I said to him, “You know, in some of the tellings of that story, it’s not a discus he uses, but instead he throws and hits his grandfather with a javelin. Do you know what a javelin is?”
The kid, probably 3rd grade or so, rolls his eyes and says with derision, “A spear…”
Like, duh, old man, EVERYBODY knows what a javelin is, jeez!
*If you don’t know the story, go read it, right now. It’s a staple of Greek mythology and the (very rough) plot of the movie Clash of the Titans, not to mention is the basis for an entire family of constellations. Everybody should know it.