My German teacher said one thing he enjoyed about America is we're very good at small talk. What he meant was we culturally always know what to say in any situation, even if it's of no importance. Germans don't, which is why they come off as rude and brusque. He really appreciated how our shopkeepers and cashiers always knew how to be polite and engaging, and how even upon meeting someone we would know how to slowly open up a conversation.

One student replied she found that to be really fake about American culture and that we pretend to be interested and friendly when in reality we don't care. One sticking point for her was "have a nice day." She said the person doesn't know her, yet is acting like her friend.

I've heard this argument before and I always respond: Well, what is the alternative? Unless you think the cashier is an asshole, do you honestly think that person genuinely wants you to have a horrible day? No, you may be strangers, but I still would hope you'd have a pleasant day, along with every other person I see in the street. Why wouldn't I want to be polite and friendly to someone I've just met as opposed to just criticizng them for what they're wearing? In that same conversation my German teacher said people in his home country would tell you how they think your scarf is ugly or your makeup doesn't match. Maybe that's not two-faced and they're honest, but at the same time, fuck you jackass. That's how fights are started. So to keep the peace, just make small talk about the weather.