A person isnt classfified a goth just because of piercings or because of wearing black clothing, but that is the typical stereotype. You wear Black and you're automaticlaly said to be gothic, well, do people look like architecture to others?
Its the realistic outlook on life. You've had a reality check, realized that everyone is slowly dying each day. Realized, you may have it better then others, realized that the world isnt all happy skippy as people make it out to be. You realize Death could happen at any time, that there is something more out there then what you know.
Gothic people have a deep sense of lyrical poetry and ability to write, using experience and life to feed off of to write, not all goths are suicidal, depressive and cutt. Goths are almost always there for others, and make close friends, and stand by them with any of their desisions. They wish to prove that you dont have to be popular and fit in. That you are your own person, that you shouldnt have to conform to what everyone else does.
the music and cloths are frequent, but you can wear pink and listen to pop music and still be gothic for your looks on life and your outlook of everything else. Most are well read, and intellectual, easy to talk to using slight slang. No one's perfect, but they are most gramatically correct having studied deep into literature and theatre.