Readjusting to life in your own country after living abroad for some time is a little like recovering from jet lag after a long flight across several time zones. It takes time. And research indicates that after nine years of living in a foreign country, you never really do readjust. Of course, things have changed, governments have come and gone, what you knew as countryside has become a suburb, new technologies have changed the way people go about their daily lives and so on. These changes may well have been taking place in your adopted country, but they were happening while you were there, so you could adapt as you went along. Those are not the main difficulties, however. It is in the smaller, everyday things that you might experience what is known as culture shock, although it's not really a shock, but puzzling all the same. For example, the precise way to behave at a supermarket checkout may have changed, and in ordinary conversation, the frames of reference have changed, and quite often you find that you don't really know what people are talking about, even though they are speaking your native tongue.