I learned that expectations are only invitations to disappointment.

I agree. One's own manners need not depend on someone else's response (or one's perceptions of same).

A paraphrase of an item I got in email, that I try to remind myself of daily: "Always be as kind as you can, for everyone you meet is fighting a great battle." The battle is seldom as visible as the inner reality of the person feeling it.

~Susan