Another teacher call -- hooray!

Talked to a new teacher today -- yay for me. I told her that she shouldn't take my son's total disinterest and failing grade as a personal affront --- he's failing 4 classes at the moment! When report cards came out 3 weeks ago he had decent grades in these 4 classes and had a failing grade in a totally different one.
But I must say ---- the kid is ingenious:
Me: "Your *** teacher called today" (I'm leaving out the subject she teaches to protect the innocent -- her!).
Him: "Oh yeah? What did she want?"
Me: thinking --- "Really?! Did he just ask that?!!!"
Me: aloud -- "She said you have an F."
Him: "Oh." (as in, "Dang -- she figured that out!")
Me: "You have four Fs."
Him: "Well, that's because ...... (get ready for this --- I swear it's true) ..... I totally concentrated on my prior failing class and brought that grade up (to a low D). It took all of my concentration and I had to let the other classes go."

I kid you not. He has the innate ability to leave me totally stunned and speechless.