unfortunately there is noone that decides whats gothic and what is not
the term was coined when a producer had to come up with something describing the sound of Joy Divison ( as far as i remember) – so “gothic” in fact has no real meaning, it could be anything from david bowie to blue haired techno fetish manga girls
and as it has not real meaning, it means something different for each person: thats why some people find it fitting to wear pvc pants together with coffin-jewellery and a top hat while others wear something completely different – for me it’s mostly a joke, something morbid and funny – others see it as deep philosphical movement – remember, ´”gothic” doesnt mean anything, so it can be everything
your neighbours might have their own idea for what is goth – it might be luck or an accident but it fits on you, what doesnt mean you HAVE to be goth if you dont want to
( what stands clearly in contrast to some people wanting to be goth but never will be goth but that’s another topic)