The sense of wellbeing! Its often with us When we are young, but then it's not noticed; And by the time one has grown to consciousness It comes less often.
There is a wisdom in this beyond the rules of physic: a man's own observation what he finds good of and what he finds hurt of is the best physic to preserve health.
Man does not live by soap alone; and hygiene, or even health, is not much good unless you can take a healthy view of it or, better still, feel a healthy indifference to it.