I have found that one of the most important things in a good marriage is ordinary, garden variety politeness, the please and thank you, minor formality, etc. The point of this politeness is not only that it is good in itself, and makes life a little easier and a touch sweeter, but that it mitigates against the greatest danger in marriage, which is that familiarity can breed contempt, or at least can led to impertinence. A little politeness, especially in trying circumstances, goes a long ways, and then, too, politeness in public makes sure that no domestic dissonance ever leaves the confines of the house. It is humiliation, no matter how minor, that one can’t forgive, or that one forgives uneasily and only over great amounts of time.