Hey, you're both [edit: mistake, see below] new here and obviously knowledgable about the topic at hand. At HN, we try to maintain civility - it's an explicit goal of the community. What this implies is that if you're in a discussion with someone, and you realize they don't understand an important point of the discussion, instead of using sarcasm, it's much better to say "Oh, I see, you're missing point x."