Has learning a foreign language taught you more than you expected? Besides grammar, syntax, vocabulary, and pronunciation, what have you learned?

Answer 1

I'm a native Spanish speaker and semi-native English speaker. Portuguese and French come semi easy to understand as a Spanish speaker but even easier with English knowledge. I can actually speak very slowly to a Brazilian Portuguese speaking person and understand 70% of the language without ever having learned it. While only knowing Spanish i could only understand 40% of it. I thought it was really interesting.