Well, living in Germany since 2010, speak fluent German and still discovering something new every day about German culture and language. In my experience, a german course just teaches you ‘book’ german - vocab, the grammar, the rules and so on. But you learn the ‘real’ German from your day to day life in Germany - from the locals. Same with culture - every region in Germany has its own local traditions and values going back to hundreds of years. You might discover something new as you travel around the country. Depending on how open-minded you are about learning and accepting new things you could assimilate rather fast in Germany (or anywhere else!)