no soy Chilena

So yesterday at work I was working in the special needs evaluation center doing Spanish translation. I said a word that the mother didn't understand "matricularse" which means to enroll yourself, (in this case enroll in school) she corrected me by saying "registrarse" which means to register. Really they both work but I guess in mexico they don't ever use the word matricularse. When I mentioned that that must be a word that they use in Chile she said, "Oh! You are Chilean!" Can I just say that after being home for 9 months and not speaking Spanish constantly it did my heart good that she actually mistook me for a native Spanish speaker.