This sounds counter-intuitive, but if you live with people that speak your native language, and you work in your native language, then simply being in Germany a

This sounds counter-intuitive, but if you live with people that speak your native language, and you work in your native language, then simply being in Germany actually holds surprisingly little value for learning the language. Why? Well, obviously it still takes a lot of time and effort, factors which aren't altered by being in Germany. You still have to put in private practise (which isn't helped by being in Germany - you can do this anywhere) and you probably need to seek out classes or lessons (which isn't helped by being in Germany - you can do this anywhere). You might want to seek out people to practise conversation with, meaning other learners, who you can also find anywere, although there are probably more in Germany. Also, my experience is that it's actually very rare that casual interactions with people e.g. in shops or restaurants is helpful - they either make no effort to help with your halting attempts to communicate (or worse: I've had some quite unpleasant responses from native Germans, even when I was trying my hardest to speak their language), or they try too hard to be helpful and immediately switch to English instead. Of course, if a person was to move to Germany, completely immerse themselves by living amongst native speakers, while focussing on learning the language, then yes it would probably help. But for most other folks where the situation is less perfect, it still comes to interest and motivation, and being in the country is of relatively little benefit.