Societal concepts of women certainly come from biology originally, there would be no concept of sex if there was no Y chromosome, but honestly to me: a woman is whoever identifies as woman. Just like sexuality, it's just an innate part of who you are. Most women are female and birth, but I don't give slightest fuck that there are women who aren't female at birth. Just like I don't give a fuck that there are men who are attracted to other men.

Like who cares. If your birth certificate says your name is Steve, but you go by Paul, who the fuck am I to protest that it's not your name given to you by your parents?

The question doesn't stump me, I just think it's a colossal waste of time.

You can identify however you bloody like, why should I care? As long as you're understanding if I mix up your pronouns, then it affects me literally not at all

Hormones are a reasonable line to draw it on, as it is testosterone that makes men strong and which makes some men dangerous