I often do a quick chromatic or arpeggio passage to "wake up" my reed if I'm about to play along with a student after a period of not playing. In this case, it really caught the ear of this beginner...
KID: Whoa! How did you do that?
ME: I practiced hard and ate all my vegetables.
KID: That's not a very logical answer.
(It turns out that he totally believed the practice part, but wasn't sold on the vegetable aspect, although he later conceded that I was probably healthier from eating some vegetables than if I'd subsisted primarily on chocolate cake the whole time.)
Later on, I did a similar fast lick when joining him again...
KID: Wow, you must know all the notes!