Unexpected "Leitkultur"

When Germany realised that it has an immigrant population (something like 30 years after the fact), it also decided that it would be a good idea to let some of them become citizens. In order to do so, a potential German would have to pass a citizenship test, just like in the US and the UK. Putting together the test required the German government to determine what is really "German," which, bordering on nationalism, stirred up a ton of angry shouting about Nazism, thoughtful-but-longwinded radio commentary and automotive arson by leftist groups.

Some conservative politician famously suggested that there is a German "Leitkultur" or "defining culture," which would allow the prohibition of wearing headscarves by teachers and other government employees and lots of other (mostly blatantly racist) nonsense. The term, however, was taken up by a lot of people as the term for what would need to be understood by potential German citizens as German.

I've seen a few versions of the citizenship test, and they're remarkably like the American one in that they only test knowledge about a country but not knowledge about the actual culture. Questions like "What colour is the flag of North Rhine-Westphalia?" or "Which of the following are highland regions?" or "When did the Thirty Years War end?" might all be fine and good for high school students of German, but they don't actually demonstrate knowledge of what Germans are like. I'd like to list here a few things that came to mind that obviously need to be tested on the next version of the citizenship test.

Germans:
love wearing socks with Birkenstock or other leather slip-ons or sandals as slippers inside

often bring these "house shoes" with them to youth hostels

often wear these "house shoes" during trips with "eingetragene Vereine" (registered clubs) to youth hostels

enjoy discussing the inane complexity of German bureaucracy surrounding these registered clubs while on trips to youth hostels

complain about but closely follow obscure rules of order during these club meetings

obsess about eating bread for supper and under no circumstances a second warm meal

fear being in drafts, sitting on cold stones and mold in general as being causes of colds, back pain, kidney infections and death

lack the self-confidence to do new things, but only for insurance reasons

(musicians only) inexplicably all own a series of small green books of horn quartets.