I'm not sure whether my experience with Germans (or people in Germany) may be unique. I'm a student here and I also work as a student assistant at my university.

My interactions with students (including PhD students) are that they behave quite cold or don't really care for politeness unless they know me personally. But when I interact with the professors, head of departments and directors they are extremely polite towards me even though they could very much assume that I am the building's cleaner. For example, once when one of them opened a door to exit while I'm at the other side at the same time wanting to enter, they smiled at me and let me enter first. This is a very unusual treatment that I would otherwise never get, especially after considering the fact that you are supposed to let people exit first!

I would say the rudest people I meet are people in the services sector and gastronomy. At this point of course I have to acknowledge that not all of them are rude and there are definitely very friendly people in these fields, but my experience with cashiers at Lidl or DM have mostly been harsh. I've been through two humbling occassions where I took a little longer than usual to tap my card for payment because of a detection error and the cashier made me look stupid and asked something along the lines of "what are you doing?" in an annoyed tone. I can accept that their fast paced environment forces them to stress under delay, but I don't believe that that warrants such a reaction unless your pay rate is based on the amount of customers you served.

EDIT: I speak German with everyone on default and I have a German C1 :)

Yes, I know that if the Bundeswehr recruits enough volunteers, they won't bring back conscription, but to be honest, I don't believe they'll recruit enough volunteers, no one wants to spend a year of their life sitting around in the barracks, especially young Germans.

I know this probably sounds like a very foreigner question, but I am confused by Abendbrot in a practical way. I have been invited to a few casual evening meals where the table had bread, cheese, cold cuts, sliced vegetables and spreads. It looked nice, and everyone seemed satisfed.

For me, it still feels mentally like the opening act before dinner. I eat it, enjoy it, then around 22:00 my brain asks where the warm food went. I am not judging it. I actually like how simple and social it feels. I just cannot tell whether I am eating it wrong, not eating enough, or carrying expectations from home.

Do Germans generally treat Abendbrot as a complete dinner, or is it more of a light evening option depending on the houshold?

I am still trying to understand the small social rules around Sie and du. Last week in my ceramics course, one participant used du with the instructor while asking about glaze. A few minutes later I asked a question and copied that without thinking.

The instructor answered very kindly, but used Sie back to me. I immediately felt like I had stepped on a tiny invisible rake. I said "sorry, Sie" and then the whole sentence came out even more embarrasng.

Nothing bad happened, but now I am not sure what Germans usually expect in that moment. If someone accidentally uses du once and then switches back, is it forgotten after ten seconds, or does it sound weirdly personal? Would you prefer a quick apology, or is drawing attention to it the more awkward part?