Every time you use the letter "u," I'm going to smack you on the nose. That's the consequence if you use that letter.
"Ow! Why are you..."
"Aagh! Okay, I get it. Only it doesn't make any sense. Why does anyone care if I use..."
"Stop it! God dammit, stop doing that! Yes, the enforcement is consistent, and yes, it's possible for me to comply. And no, there's no concept that I can't convey absent that letter, if I make an effort. Still, it's not necessary to enforce this restriction. It does no good and prevents no harm. As far as I can tell, y... the person I'm speaking to merely decided to do this. Why am I--and my nose--held responsible for that?"
"Oh, and I'm really getting sick of this, so... FUCK YOU!"
You know what the problem is with kids these days? They just can't handle consequences.