I'm an old, so take this with a grain of salt. (But also I have experienced gender confusion myself. Maybe that qualifies me for something.) Here goes:
I don't understand why it's important to people to identify their gender so specifically to what they feel. I'm a man, but I don't always feel like the stereotype of a man. I often get a little giddy at sparkly pretty things, for example. I would like to wear dresses sometimes. I do not like the chest thumping guys do. In other words, I sometimes act or feel in ways that people call womanly. But I'm not a woman, and I'm okay with that. I'm a guy. A guy who sometimes acts "womanly" or "feminine", true, but that contrast is not my problem, it's a problem with the way society understands gender, right?
I 100% believe that some people are born with a body that does not match their gender. I know that to be true. But I also think sometimes people feel like they don't fit the mold they hear society telling them they should fit and conclude that therefore they are not the gender they were assigned at birth. Why give "society" so much power over such a personal, individualized, experience?
But, you know, the world we live in is a group effort and there are others who do not feel the way I do. Some people want that ability to label who they are in a way that the old school labels can't provide, and maybe those people will be the ones to shape the future of our understanding of gender.