You know the one. It's a tiny bug, a problem that only comes up once in a blue moon -- if it's even a problem and not just a slight problem like a model clipping issue. You really shouldn't care one way or the other, it's so irrelevant... but you care. You can't help but care. The very thought of it bothers you. And even though it's something so obscure that you're not sure if anyone has even bothered reporting it other than you, or so rare or so unnecessary, you still get angry when all sorts of other minor bugs get fixed and this one persists.