Have you looked at your keyboard lately—not just a glance, but a detailed inspection? Probably you didn’t, because if you did, you’d realize how filthy it is. That is, unless you clean it regularly. But most people don’t. The nature of a keyboard is such that it’s a dirt trap. The recessed area where the keys sit is an invitation for dust, grime, crumbs, hairs, nail clippings and other detritus to accumulate.