It is very easy for people who do not have an experience of a gender identity to deny that there is such a thing.
Gender means group. Or class. It means shared traits within a class containing many people.
It is 100% IMPOSSIBLE to have an identity that is 'gender'.
You can have an identity.
You can imagine that this is what other people also feel.
You may find a portion of people who agree SPECIFICALLY with you when you describe your specific feelings and identity, and you can certainly describe THAT group as a shared identity of sorts. But that group isn't ever going to be 'female'.
What you categorically can NOT do, is find a sub-sample of an existing group (people who all have XX chromosomes), IMAGINE that you share feelings in common with some or all of them, extrapolate that to the entire group, and then declare that you possess the 'gender identity' belonging to the entire group. Because the group themselves don't even share an identity.
It's possible to wish you had a different body.
It's possible to hate your own body.
It's possible to erroneously associate personality traits with one reproductive type.
It's possible to possess those traits and be the opposite reproductive type.
It's possible to reason falsely that you are an exception to the 'rule' rather than concluding that you are the evidence that the rule is wrong.
It isn't possible to 'possess' the 'identity' of an entire reproductive type.
Not even your own.
You can only know the experience of living with your own body.
Never anyone else's, let alone a group of billions.
At best, you can find the words to describe your life and experiences and some other people can agree that they too share them. And then, you have a common group experience of sorts, that you all agree you share. Finding your tribe, giving yourselves a name.
It frustrates me that people do not reason this out.
When anyone uses the word for A REPRODUCTIVE CLASS to name their feelings, they are co-opting me and every female person into their statement of who they are.
If a child or an adult claims they have a gender identity - the question needs to be asked 'what do you mean?' Until you uncover their true belief. And on the way you have to unpick every false idea that society has planted there.
I am female.
I share my reproductive class with billions of others.
But I don't share an identity with them.
I cannot and will not co-opt other people unwillingly into a class with me based on feelings which they may not share.