A childhood belief about places

When I was younger, we had a giant satellite photograph of the British Isles hanging in our hallway. There was a small strip of land at the bottom of the photograph (northern France and northen Belgium). One day, I asked my mother what country that bit of land was, and she told me it was France. For years afterwards, I believed that France was a long, thin country, covering pretty much all the coast on the other side of the English channel, and that it was part of the British Isles.