@marmanold When I was relearning German a few years ago so I could help my daughter learn it, I found the same thing—realized that in school we practiced one-on-one conversations and formal presentations but never said y’all. I still have trouble remembering 2d person plural informal conjugations. (Though I think I figured it out while practicing on my dogs, to be honest. Both of you, come!)
Incidentally, I also practiced by texting my daughter in German (and adding the German keyboard as an option to my iPhone), which continues almost five years later to screw up the autocomplete function. I consider this a victory over the tech lords.