Bilingual thought.
I have a habit of slipping into the formal form with my dear friends, as a mark of love, because Usted vs. Tú has tonal range, and can often go full circle to intimate respect.
It's something I haven't quite fixed in 6 years (though I'll always catch myself and go back to Tú), but I think it happens because my native-English brain *loves* this range of respect/adoration we don't have in our own simple "you".
...But we DID once, with thou vs. you!
Should we bring it back? 🤔
The problem with returning to our old division in English is that we've completely swapped the meanings in colloquial usage.
"You" was once used to refer to someone of higher class standing, or for general respect.
"Thou" was then used for someone lesser, or in more familiar contexts.
But because "Thou" fell out of common use, average people now think it's fancy, and thus only to be used in formal contexts.
A few more everyday "thou knave!"s and "thou cur!"s should set us right, though! 😁
I read that in the voice of Ripley and I was not disappointed. :)