You were able to sing something they related to instantly, because it was part of what you felt. It was part of what you had already traveled through. It's part of the people you were associating with daily. It was all of that.
If French is no longer the language of a power, it can be the language of a counter power.
It's definitely a thing to be sitting there, getting a pedicure, and you look over and someone is reading an article about an aspect of your life that you know is not true. It's weird, it's uncomfortable, but I don't see it changing anytime soon, so I should figure a way to laugh through it.