According to the foremost authorities (who shall, at this time, remain anonymous), nothing is perfectly clean. Everything is dirty. Nothing is not clean. Because nothing does not exist. ?!?!?!?!?!?!
No, really. Both physically, and mentally, nothing can ever be truly clean in our world. I say this to satisfy the religious beliefs of myself and other people who might read this. But let's keep on topic.
For example, right after you have a shower, you start sweating again, and that minuscule amount of bacteria that you left on your skin begins to grow and multiply, and after a few hours of blissful unawareness, you start to stink again. I won't make a pun here, 'cuz that would be way too cliche. Another example then. A carpet, car, or piece of furniture can never be truly clean, because right after it gets washed, the lingering molecules and dust motes that float around in the air settle on it, and then all the spores land on it and start to multiply. Slowly at first, then faster and faster as the growth rate expands exponentially.
Then there's the mental, "clean". I suppose that you are clean from the moment you are born, but at some point, the human instincts and desires take over and we succumb to whatever they dictate. In addition, society today is so saturated with things can can be classified as, "dirty", that it is impossible to remain clean forever, for just like the dust motes on the furniture, once washed, the inevitable will eventually grow again.
However, there are those small instants in between when we are clean, and our bodies are clean, and our carpets are clean. Those blissful moments, like when you smell that fresh, kind-of-like-plastic scent of clean carpet, and that breeze that you feel as your hair starts to dry. And that sense of accomplishment you get when you rid your mind of all impure thought and focus on the sublime.
Psssht. Tsch. Yeah, whatever.
Bad is here, and it's here to stay. It's up to us to keep washing, for those moments of clean carpet scent are what makes this life worth living.
P.S. I'm sorry if I have grossed you out or disturbed you in some way. Maybe I should have put some kind of disclaimer at the beginning?