Its the first time i've ever seen autodidact(ic). I assumed it meant self-taught based on context, probably like most of the others.

OK, probably I only know all the weird words you never actually use.

That actually happens a fair amount with non-native speakers, since our uncommon words are sometimes very similar to their common words. For example, an italian recently called me ascetic, and I had to look it up.

"Autodidacta" is the most common way to say "self-taught" in Spanish.

I love how English is quite happy to absorb new words, even if the English speakers only know a subset!

Back in school, we were warned about "faux amis", words which sound like they'd be right to an English speaker, but very much out of place to a native French speaker. I think in English we'd just accept any and all alternative meanings and let context sort it out, who's up for some creative reading?

Yeah, in Spanish it's not unusual or fancy.

In French (autodidacte) it's pretty much the canonical word for that concept, too (French is similar to Spanish in lots of ways).