<<serbian and croatian are so similar they are considered one language

BYB: this is an actual question and is not meant as an obnoxious reply [gesture of friendship emoticon]

I remember hearing, while living in Germany in the early 80s, a couple of stories from people who, while visiting Yugoslavia, spoke Serbian to Croats, the effect on whom was extreme. These may have been the apocryphal travel tales of tourists who, finding insufficient adventure in their real-time wanderings, sought it out in the telling. Or banish the last sentence and say if these tales are not, in fact, just embellishments, they suggest there *is a substantial difference between the two languages. What might that difference be?

IP