Kids Continue to Say the Darnedest Things About Musical Symbols

To set it up, here's a rerun from two years ago this week:

A beginner had his first "line" from the book that actually lasted more than a single line; as often happens, he stopped at the end of the first line.
ME: So how do you know you're not done when you get to the end of the first line? What's missing?
KID (points to double bar): Black thing!
ME: What's the black thing called?
KID: Black thing!

That one cracked me up so much (mostly because the kid said it with so much determination) that I've mentioned it to subsequent beginners upon their arrival at that line, and it's become a running joke between me and some of this year's crew.

So one of them was fooled by the two-line line recently, and I asked him the same thing...

ME: So how do you know you're not done yet?
KID (points to double bar): It doesn't have that thing right there.
ME: What's that thing called?
KID : The stopper?