Seems to me that teaching rules (of composition, among others) is not too far from raising kids, especially teenagers. You try to instill some wisdom and experience, but all you get is an indifferent stare, if they even heard you behind the earbuds and headphones. Or, at best, "Yeah, dad, whatever" or "Cool story, bro." They might ignore you, mock you, curse you even.
At some point in the future (be it the next day or years later), you realize they actually heard you, internalized it, and even acted on it. And sometimes they would even admit it: "That's how you raised me, dad." And you think: "Really? You actually heard me and remembered it from (days, months) years ago? Wow!"