Conversations with my Son: What the Hell are They Teaching You in 2nd Grade? Edition

So it's the end of the day and I'm hanging out in The Boy's room for the requisite "FIVE MINUTES, MOM!" before he goes to sleep.  We're having our usual conversation, which ranges from playground politics to theoretical discussions about who is the strongest Jedi to comedy theatre starring one stuffed Knuffle Bunny, and I tell him that it's time for me to go so he can get some sleep...

The Boy:  It's been five minutes ALREADY?

Me:  Yep.  Time flies.

The Boy:  It doesn't really FLY, like flap around.

Me:  No.  It's just an expression.

The Boy:  Like, "raining cats and dogs."  It's a...a...

Me:  Expression?

The Boy:  No.

Me:  Saying?

The Boy:  No, mom.

Me:  Hyperbole?

The Boy (frustrated):  NO!  It starts with an "I."

Me (moment of confused silence, followed by moment of "he couldn't mean this, could he?"):  Idiom?

The Boy:  Exactly!  Idiom!

Me:  You're talking about idioms.

The Boy:  Yeah.  And really, the fact that Amelia Bedelia thinks idioms are real?  What is up with that, mom?

Me:  Well, it's just a humorous device the author's using to make the books funny.

The Boy:  Idioms aren't real.  And Amelia Bedelia is not very smart.