Ah yeah, that was me as a kid too. I read whatever I could get ahold of, which was mostly English and French from 50+ years ago (yay, secondhand books and copyrights expiring). So my vocabulary in both languages was (and occasionally remains) antiquated. My pronunciation fixed itself some time after university, but was weird in my youth.
I've since de-prioritized human language, for practical reasons. Communicating with machines efficiently is simply much more productive (and lucrative)! My shorthand also is it's own language, where there is no distinction between letters and numbers, of which there are 16, and they phonetically map to English. Hexadecimal English, or Hexen for short. It's optimized for writing quickly (every character is precisely 1 stroke).
Quite handy for taking notes around people I don't want reading them, too.