You've heard of Serbia, Wallachia, and Moldavia, but would like somebody to explain to you exactly what Croatia, Bosnia, or Yugoslavia are. When somebody does, you say, "Oh, well, I remember now, Yugoslavia is the name of the big Serbian empire."
What happens next really depends on the ethnicity of the people you said that in front of...
Slovenes, Croats, Bosniaks: RAEG
Albanians, Macedonians, Montegrins: rage
Serbs: Joy