There's always more to be said, but I did answer a very similar question not too long ago:
When people in the Roman Empire ca. 410 AD say the word "Goth", they were thinking of barbarous tribes that came from their northern border. Now, when people say the word "Goth", we think of ruinous castles, gloomy churchyards, and teenagers with heavy eyeliners. How do these two meanings relate?