I've been on here defending transgenderism and now it's too much to respond to, so here's my defense in one thread: (incoming downvotes, allat, and other dismissals)
Some of ya'll on here are confident as shit that there are only two genders, and I'm starting to believe you were never taught the difference between sex and gender.
So here it is:
Sex (as defined by Google):
"either of the two main categories (male and female) into which humans and most other living things are divided on the basis of their reproductive functions."
Now here the important part is "on the basis of their reproductive functions," because this is only a small part of who we are. I mean whose first response to the question "Who are you?" is to answer with what their genitals are? No, you would respond with characteristics of your personality and important aspects of how you want to be known (most of which I would assume are not physical features).
Gender (as defined by Google): "the male sex or the female sex, especially when considered with reference to social and cultural differences rather than biological ones, or one of a range of other identities that do not correspond to established ideas of male and female."
I know some of you are going to read the first phrase and run to the comments parading, but the important part here is "...or one of a range of other identities that do not correspond to established ideas of male and female." But especially the "established ideas of male and female," is the part where people don't seem to understand. See, what our concept of gender is, is made up. What makes something masculine or feminine is completely arbitrary. Like why do usually women wear dresses and men usually don't? Or why are men traditionally perceived as the providers of the family, while women are caregivers? These are just a couple of examples of how gender has been socially constructed.
Now comparing the two, what in the physical description of someone necessarily indicates things about how they should be? Or rather why would someone with XX chromosomes be more likely to wear a dress than someone with a Y chromosome? Without gender there is nothing to interpret what those chromosomes mean. And thus, you end up with two, everchanging notions of what a man and women are. But those are just two ideas of what someone can be, and not everyone falls into either of those categories. And since gender is not necessarily a physical descriptor, but rather a social/cultural descriptor, someone can choose whether to abide by that label, or another label or identify with something completely different.
There is more to go into, but I'll leave it at that. I recognize that this is kind of a lot to take in, and I've been a little confrontational today. This isn't really an attack so much as it's just trying to be informative. I hope this was somewhat helpful. I just wanted to share this considering transgenderism gets brought up a lot on this site.
TLDR: Gender is a social construct and is different than sex. Evidence of this can be found by analyzing the origins of our notion of what a man and a woman are. Thus, there are more than two genders.