That is interesting - when I was working abroad and only spoke my second language, English, almost exclusively every day for a good three months... it did feel

That is interesting - when I was working abroad and only spoke my second language, English, almost exclusively every day for a good three months... it did feel strange and unfamiliar to go back to my native tongue of German at first once I was back in Austria. I haven't forgotten anything, I just initially had to make a more conscious effort especially since some things are a lot easier and more "fluent" to say in English somehow.