It's self discovering... once you figure out how to use its very eclectic by modern standards mechanisms for discovery. No sarcasm. Learning how to use it is a skill you have to actively acquire. This is more a criticism of emacs than of you.

That said, I've been using it for... uhh... about 30 years now, and I've honestly never picked this skill up myself very much. I can only use it minimally. Just googling is fine, and as others have commented today (although maybe in that other thread about emacs), AI makes it even easier because it can just straight up write the modifications for you if you need them.