CAN change your genders being simply how you feel or identify.
CANNOT change your sex. Only your appearence.
This idea of gender as a feeling is utter bullshit, and is purely a creation of individuals being poorly adjusted to a sexist world. There is no such thing as "feeling" male or female. That's like saying you "feel" like a dolphin when you are a human. The only reason people "feel" like they are the wrong gender is because society is hell bend on defining a person's quality in terms of their gender.
I am a man. I'm nice. I'm sensitive. Hell, I'm sometimes moody a **** and every time some new blurb floats around on facebook about how to translate what a woman really means when she says such and such, I usually find myself thinking "well shit, that describes me pretty damn well too." But I don't "feel" like a woman. I am not a woman. I am a man. I have a certain personality. My personality is equally valid for a male or a female.
The only reason why personality leads people to "feel" like they are in the "wrong" body is because they are poorly adjusted to coping with the social injustices related to measuring human individual worth in terms of personality being adequately male or female.
I really do feel sorry for Bruce. He's had to live with those stupid twats the Kardashians for so long, watch them obsess for years over the most inane and superficial qualities, and undoubtedly endure all kinds of abuse. His wretched family has driven him crazy, and now his mind and heart are broken to the point where the only way he can figure to get himself fixed is to get an operation so that he can spend the rest of his life living a lie. It's his life, and his body, so he can do whatever he wants with it. But let's not make any mistake about this. The transgender "phenomenon" is nothing more than an escape into a fantasy world, caused by an abhorrently violent sexism that runs so deep that the "advocates" can't see that they are in fact the biggest proliferators.