I've always felt I was somewhere in the middle! I've always hated it when someone would put me on one side or the other.
Something that's happened to me more than once is getting tagged as an extrovert. So if I volunteer for random task on stage at a workshop I'm attending, someone inevitably will always say to me, "You must be an extrovert." I usually smile and node, but this secretly gets under my skin because I know it's situational.
Looking at extroversion as a spectrum makes so much more sense and now I've got language that better describes my place on it. Awesome!