I think that if you have this inner sense then you can't understand what it's like to not, and if you don't then you can't understand having it.
And that's ok. Everyone is different.
But then you get the fact that
Gender ID stuff has come from trans people who by definition have this feeling, extrapolated that pretty much everyone does. As far as I know there's never been a wide study with proper explanations, definitions etc to find out if most people actually do. And it would be hard to do it as there's no description as far as I have seen, and most people if simply asked their gender will say their sex.
Certainly for years and years many women on here on various threads in chat etc have said no they don't have this feeling. Why is this ignored? That according to stonewall makes them all trans, so why are their views discarded? Often with the 'they just don't know their own minds' shit that had been pedalled for years.
And then of course there's changing laws and breaking down well established social norms (who goes where in mixed changing etc) based on what. A feeling that no one seems able to explain, which is not visible or measurable, and that seemingly is not nearly as universal as assumed.
This whole thing is based on wants and feelings. Attempts to get to grips with the logic of it etc are just shut down pretty much everywhere except here. Well and presumably some dominantly male websites I expect but I have heard they don't get the same attention as Mumsnet.