We're talking how dirty it feels after a week or two without washing. We're not talking about dreads.

If it doesn't matter how "often" or "infrequent" you wash your hair then your hair would have to feel perpetually dirty and clean at the same time. Never one or the other.

@WilliamHenkel: No it always FEELS dirty and LOOKS clean. They aren't both feel.

I'd rather it look clean, even if it felt dirty. No where does it say that it's actually dirty.