Of course I've been to the Republika Srpska

I was about to to leave Sarajevo for the next country in the Balkan leg of my trip, when a friend online asked “So will you be visiting Republika Srpska?”. My feeble reply at the time was “Uhh..yeah maybe I might.” Then I went to google online to find out where exactly Republika Srpska was, and why I have never heard of this country before.