I think eventually it comes down to that, doesn't it? I decided recently to just stop trying to work it out because there didn't seem to ever a bottom to the pit that is gender. The more I looked, the more there was nothing firm there. So I decided to settle on 'I don't know and if it wasn't for the rest of the world trying to fit me into their boxes I'm not sure I would care.' Which you can lable as nb/genderqueer for convenience, I think.