See, the problem is, far, far too many people can't just extrapolate a little.
Now, I don't know whether this is the case or not, but I have read quite a bit, and a lot of the trans women I have read about have said, in essence, "I've been a girl all my life -- I've just got this deformity, this outie where there ought to be an innie."
I am trying to get you to see that a trans person has a gender which is part of their psychological, their mental make-up, that conflicts with their sex, which is merely biological.
Now, I can't speak for you or anybody else, but when I really try to think about "who I am," it turns out that my body is a very, very small part of it. I am so much more than chemicals and morphology.