Hmm I've also realized why Arthur is recognizing my musical flaws OD'ly: Because I'm "smarter" then him. So when I make a mistake, he feels more superior to have noticed some "conspicuous" wrongdoing that an "astute" person like me has committed. Actually, this happens for another person as well - you know who you are. And I've told you to shut up about it, but you just don't.
Quite frankly, it's getting pretty annoying and so obsolete that what you say doesn't really make sense any more, nor does it affect me.
So please, if you want to correct someones' musical mistake so bad, then become a teacher. For now, just shut up if I mess up on a word or played a measure too early. Nobody really cares. And if you want to feel so superior, I suggest actually doing something noble for a change - rather then just sit on your ass all day.