Do's and Don'ts.
Because Germany doesn’t necessarily issue resident foreigners with a document like a green card, alien registration certificate or carte de séjour, you really need to carry your passport with you at all times.
True, stop-and-search swoops are rare in Germany, but you have to be able to produce official identification in all sorts of humdrum situations like picking up a package at the post office. Our advice: play the game.
Birthday congratulations - superstition prevents Germans from enjoying birthday wishes in advance, because it is believed to bring bad luck. Also birthday gifts not welcomed before the actual day but belated congratulations are expected and widely accepted.
Crossing a red light - It is normal in Germany to obey the traffic rules. Even pedestrians do not cross a street on red light when the street is empty and car traffic seems far away or simple is not visible for a longer time. It is widely regarded as very rude to cross a red light by foot when children are able to watch you jaywalking. If police are in the vicinity, they will often fine you.