The strangeness of acquaintances

I truly love the kindness of strangers, one of the best parts of life....but what about the strangeness of acquaintances? That dirty feeling you get after spending 20 minutes talking to someone who you do not like for whatever reason.... That "hows work, hows the family" fluff when what you really mean is "did you finally get a job? and hows that slut your dating or the one your cheating on her with?". That one moment when you wish that you were an ass hole and said just that or better yet said NOTHING and walked away. What is to be said of that? Is it wrong to fake sincerity when its only purpose is to make life go more smoothly? Or what about those times when you apologize when you know for sure that you have nothing to be sorry for... is it wrong to lie about regret or remorse if its only objective is to keep people from being angry? They say honesty is the best policy.... but to what extent?