It always amazes me when someone just assumes that US companies are somehow superior to the rest of the world. I've worked for a couple of US based companies and the experience was shit compared to other non-US companies I worked for.
However, you do expect some kind of "business culture" especially because the company usually forces the advertisement for it onto you whether you want or not. Our floor are plastered with Fremdscham posters and phrases in english. Often you also hear a manager in a meeting praising some new trope from the East Coast regarding office layout or similar.
What really sticks with is the informal "you" though. It's really helpful most of the time.
Noone ever asked, 'hey, what have you been doing in the bathroom for the last 10 minutes??'
Seriously, since I wrote this, I really thought about what may happen if I try. I thought maybe some people would be too polite to wake me up. Others may try to call me but I know at least one that would kick my door in just to see my shocked face. It would cause some talk for sure. I see things going this way: "Aluhut is not getting enough sleep at home...maybe he has some trouble with his girl" or "...he's partying through the whole night! I'm sure about that!". Whatever it might be in the end, I'm pretty sure it would all focus on the fact that I've done something wrong causing me not to be fit for work.