Around the year 1999, I saw a documentary about hermaphroditic humans. Apparently, it's about one in 100, or greater. If true, that means we've all know hermaphrodites.
Watching that documentary, I was in the midst of trying to get pregnant. Those ideas made me remember when I was 13, in Jr High, and we all took a test to prove how different male and female brains are. I was the outlier. I was the girl with a "male brain". It didn't help that all of my school friends were guys.
So, when I finally got pregnant in 2003 and had a ultrasound, I HAD to ask the tech "Will you look at my ovaries? Are they normal?" (I was wondering if I might have a undecended testicle up there.)
Apparently my plumbing is fully female.
But, you don't HAVE to be a literal hermaphrodite to be genderqueer.