I've also encountered this.
It doesn't bother me, but occasionally you get people who are so happy being ignorant, that if you try to correct them they get quite nasty.
couple Christmas ago I told a lass that Elvis didn't write always on my mind, and she screamed at me and called me some rather unsavory things. Of course she was all eyelashes and attitude like
I worked with a girl in the early nineties who had no idea that tea had ever come in anything other than a teabag