You're walking along the street, lost in thought and a polo wearing douchebag with perfect teeth and a self assured strut says "Smile!". Has this ever happened to you? If so, you're probably a female living in the United States suffering from something commonly referred to as "resting bitch face". The fact that a normal, expressionless face is even given a name (a negative one, at that) is disturbing to me, because it denotes that there is something wrong with your mug if your lips are not turned up in a cheesy grin 100% of the time.
I've been told that some Eastern European country (Russia, I believe) has a saying along the lines of: "the only people who smile constantly are either crazy or American". My fellow Americans, there's nothing wrong with the rest of the world because they don't share our affinity for smiling, nay, it's our obsession with baring our pearly whites that is weird. So that German cashier is not grumpy or rude, they are paid (minimum wage) to do a good job, not to smile their way into your hearts.
One thing that many non-U.S. Americans don't understand is, that smiling is part of our cultural etiquette. If you don't smile, you may be considered rude or stuffy. First impressions are truly vital in the U.S., and if you don't put on a good face when meeting a potential boss, friend, partner, etc., then you may just throw a perfectly good opportunity out the window. On the flip side, Americans take this etiquette as a global fact instead of a cultural phenomenon, and become offended by people from other countries that don't follow this (U.S.) norm. In my opinion, it's always best to understand your own customs and the customs to other, in order to avoid conflict or misunderstandings.
Personally, I love the fact that Germans don't smile all the time, because it means that each smile from a German is a genuine expression of joy! Now isn't that just a lovely concept??
I've always loathed having strange men telling me to smile. I find it condescending, abrasive, and completely inappropriate that some bloke I've never spoken to thinks he has the right to demand something of me, of my body. I'll do what I like with my body, with my mouth, and if that involves not smiling for randos then so be it!
And with that said, I'm off to work, where I shall walk along the streets with my resting bitch face, unharassed by people trying to impose their will regarding my facial expressions. Thank you, Germany!