This is the logical proof that disproves transgenderism, aka gender ideology.

According to transgenderism, if your gender is different from your sex then you are transgender.

Also according to transgenderism, gender is not the same thing as sex.

Therefore everyone's gender is different from their sex.

Therefore everyone is transgender. You, me, everyone.

Alternatively, transgenderism is not correct, and gender is the same thing as sex.

In that case everyone's gender is the same as their sex because it is the same thing. Therefore nobody is transgender.

It is not possible for some people to be transgender and some people not to be transgender according to the definition of transgender.

The whole of gender ideology is built on this idea of gender (identity) which can supposedly be different from your sex, and that's what makes you transgender. This shows the flaw in that argument. You can use the term "gender identity" instead of "gender" in the above proof, and "biological sex" or "sex assigned at birth" if you prefer, it makes no difference.