English developed from German. In a much longer amount of time, American English could develop so different from English in Europe, I would need to purchase a phrase book to go on a tour of England.
Ok, fine, to sum it up, I don't like it when people come over and tell me I'm spelling something wrong, when it is an accepted spelling the US, assuming, if I went to the National Spelling Bee, and spelled apologise that way, my spelling would be accepted, and I would be participating in the next round.