"...your English is excellent!"

I've been told that by Swiss peole several times since moving here almost four years ago. I guess that they don't realize that I grew up in America. Today, I was renewing my gym membership (I enhanced my membership to include unlimited classes...I begin yoga again next week after a nearly five-year absence), and I began speaking to the gym employee in German. At one point I must have looked confused, because she asked me: "Do you speak English?" I told her I did, and she repeated in English what she had just told me in German. After about a minute, she asked me what nationality my last name is, and I told her that it's Finnish. To this, she replied: "Your German is totally understandable, but your English is excellent!" I just said thanks...it wasn't worth going over my life story.