I actually took 5 years of it in school and used it to communicated half and half english/German with Polish relatives. I am about 9-10 years out of practice though. I rarely use it, but here and there I throw it in.
That is kind of interesting, because I`m living in a town which is divided in a German and Polish part.
Your German is not as bad as others, but it is strange that many people from the U.S. are writing with me in English first and then suddenly they begin to write in German. Is it possible that I`ve found something like a secret German support base!? Or is it just because they`re interested in this language... who knows