Maybe it happened tou as well, just as it happened to me. You speak a language that is not your native language ans some tries to guess your accent. I can even happen when you speak your mother tongue that people try to guess where your cradle stood. You do not speak like people from town A nor town B, so where are you from?
The Tanzanian writer Stephen Swai tells about his experiences and his ideas about his and other accents.
Read about it here.