That is one of the strangest things I've ever heard. Did it ever occur to that student that in the old days foreign rulers did not force their subjects to adopt a new language? I can't even come up with a single instance where this was the case. I can't quite imagine some medieval administrator going to the countryside to teach peasants a new language.
Nevertheless, there may be a genetic component to the language-learning ability of Japanese, though this would have to be evidenced first.
Like most Germans, I only drink Pilsner. And like most Germans, I stick to my local beer, which is Wernesgrüner. Foreigners coming to Germany might be a bit shocked about the beer selection in local restaurants. Usually we only serve one single beer, which is the local beer, because Germans are quite loyal to their local beer. Germans usually don't care about beer variety.
Also, Berlin doesn't really feel German anymore.