That’s wonderful! I have a similar background and am also surprised at how I learnt and still remember it even though it is quite distant from modern Persian
Yeah, I imagine it's closer to Pashto than modern Iranian tbf. Ossetian is another outlier here, close to Georgia/Russia but related to the languages from Pamir/Tajikistan.
Avestan (IIRC, my memory is fuzzy) had some weird similarities to my native language—Polish. Occasionally I'd stumble upon a phrase I could actually understand.
Random example I just remembered: "both ears" (again IIRC) sounded like uba ushi /uba uši/ (uba being 2 in dual, ushi meaning ears). Polish used to have dual number, but now retained it mostly for some body parts ( oba == 2). Ears in PL is uszy /ushee/. You'd sound a bit weird saying saying "oba uszy" in Polish, but people would understand you.
Nowadays I just enjoy the fact that Ashem Vohu is one of the oldest phrases I can utter in its original language. (I'm really good at learning and forgetting languages it seems.)
