We did a 9-hour drive to Berlin, stopping a million times along the way, catching up on what's happened in the last 10 years, and going way, way, way too fast on the Autobahn.
That evening, we ate at a super crowded/popular restaurant in Germany and made the mistake of asking to take home our leftovers. The waiters simply could not believe our request and the people at the next tables laughed. At first, the waiters suggested that this was only possible on weekdays, but definitely not on a Friday night. Only then did I remember from my German classes that this is a "no-no" in Germany. It worked out fine though: they let us take home our delicious leftovers and we tipped American-style :).