I'm pretty sure everybody can do it wherever the average is. It's a matter of wanting to do it, that's all. Foreign workers come and pick up whatever host country language yet they're not always the brightest and also don't have exactly ideal conditions to do it. Like a sibling comment touched, you can go to Berlin and complain the language is difficult, talk English with Berliners happy to practice their English, and you'll come back learning almost nothing while they'll polish their English without even needing to travel outside Berlin. Because of choices. Learning something new is a challenge and like with every challenge, can be accepted or not.