I grew up in Austria spending my summers in Croatia. My Croatian certainly isn't perfect, but I'm fluent and my Austrian friends certainly never get the feeling

I grew up in Austria spending my summers in Croatia. My Croatian certainly isn't perfect, but I'm fluent and my Austrian friends certainly never get the feeling I'm unable to express myself when I'm talking to Croatian friends of mine. I always start shaking my head when either Croats or Serbs tell me that they speak different languages, because frankly, I can't even tell them apart. Sometimes they find my notion of their languages' sameness offensive, which in turn I find offensively childish.