Consider the difference between a bikini and a burka. Which is the essence of womanhood? Neither. There's nothing essential about either. They are just a choice -- made by individuals and often enforced by societies. That's gender.
Consider the women who helped us win World War II by working in factories (Rosie the Riveter). Or the fact that you can read and write. Both of those were considered contrary to essential womanhood in previous eras. That's gender. It's a social construct -- that changed when we needed more workers.
But the ability to bear children, yeah I cannot do that, so it's not a choice. That's sex.
There I just explained it.
I reply:
Massive fail. You have not proven that gender identity, in the sense you mean it, exists. Doing the standard left-wing "repeat after me" mantra doesn't work with me.
A bikini and a burka are ESSENTIALLY similar in that both are items of dress that women wear depending on their society - and all women of child-bearing age (except for a few atypical people) want to be attractive to potential mates.
Kudos to Rosie the Riveter, but none of them left their guts, balls, and brains on the beaches of Normandy, or other battlefields. Without young men, Rosie the Riveter wouldn't have had to work in those factories.
That I can read and write is entirely a function of modernity and its need for a universally literate society.
Margaret Mead (who has been terribly misunderstood) pointed out that In all societies, tasks that are associated with women are low prestige. Tasks associated with men are high prestige - even when they do little to contribute to the actual physical survival of the society. In one society in (I believe) New Guinea, men dress sacred dolls while women do pretty much everything else. Guess who gets the credit and the prestige? Men.
This is because men value extra-familial pursuits more than women.
I am not saying that men and women are not mostly gender typical. Of course they are - but this is an entirely biological function. If you want to dress it up with a lot of talk about "gender identity" go ahead - but please at least concede that said gender identity is a function of biological sex.
Otherwise you might as well be talking about a metaphysical "soul" which, come to think of it, is exactly what your "gender identity" is: it's a soul for modern atheists with no core identity in their sex, country, religion, tribe, etc.
Again, you "won in a rout" because your side was an advantageously-placed elite, not because you had sound arguments. Now that some people have taken your ideas to their (crazed) logical extreme, you cry foul.