I know. I can read a book from some latin author and understand everything in it, but when you listen to a Spanish person (being born in Spain) and someone from South America it sounds totally different. Even in Spain there are many accents, but the differences ain't as notable as they are when you compare it with Mexican or whatever.
Kaicui calls himself Spanish but then he mentions "puerto ricans/dominicans/etc...", that's not being Spanish, that's being South American.
You wouldn't call a British guy American, would you?