I just bought myself a very nifty necklace: it's a small level on a chain. Now everyone can tell at a glance how off-balance I am. But it got me wonderin': why are things UNbalanced instead of IMbalanced? And why do we talk of IMbalance instead of UNbalance? You'd think we could use the same prefix for both! (Well, maybe if you're more level-headed, you wouldn't think so, but I do.)