A person with a boy brain and a chopped off penis, is still a boy, dingbat.
A person with a girl brain and a penis reshaped like a vagina, is a girl.
The penis and the vagina are really just an outie and an innie of almost the same source materials.
There was a boy in the sixties who got his penis mutilated by a botched circumcision. The doctor thought, like Floppy here, that the penis was all there was to a boy, and so they decided to let him live as a girl. It didn’t work; he felt wrong in the “girl” body and at 15, he went back to living as a boy. But his life was already damaged, and he killed himself later, due to depression and financial troubles.