I worked in the south of England a while. The first couple of weeks people asked if I was from Canada or the US. The next few weeks they asked if I was from Australia. By the end of the second month they thought I was Irish. I didn't deliberately change I just have an ear for languages and accents and pick them up relatively quickly. My dad was the same. When I got home It took several months to switch back and I would revert when speaking to someone with a British accent or even occasionally when telling travell stories.