Cleanliness, in the American cultural sense, is most definitely learned behavior.

[insert childhood horror stories about bathing] Which is why I still dislike the whole process and I put it off for as long as I think I can get away with it. When I was unemployed I could go for a couple of weeks with nothing more than a damp washcloth on the visibly dirty parts. I work with food now so I've got to be on top of things.