Lately I noticed that I cannot even speak my native German dialect as easily as when I was a teenager (I moved away from home to university when I was 20). I often hesitate because I am not sure whether some word I said was correct in my native dialect, or the local dialect where I live now, or the dialect of my wife (Swiss German). At home, we speak a wild mixture of 3 different dialects and standard German. Our 5-year-old mainly speaks standard German because that's what they speak at kindergarten (most of the teachers don't speak the dialect, and there is a significant number of French, Italian, Ukrainian, and Syrian kids for which learning the dialect would be even harder). At work, I speak a mixture of English and standard German.

After living in Germany for nearly 10 years, but working in Switzerland, my wife recently had an identity crisis because a Swiss colleague thought she was German, and had just learned Swiss German very well.