I derived mine through scientific observation the way we detect black holes through the behaviors of nearby bodies (or through gravitational lensing and accretion discs).

Gender is very important to some people. We see this with trans folk who will suffer social stigmatization, take hormones and undergo medical procedures to identify as a gender they weren't assigned at birth. We see this with alpha males who do not feel masculine enough, no matter how big the bumper nuts on their wide-bed SUV.

I don't feel this at all. I have an [M] on my state ID. My body has the boy bits, but meh. As a young adult, I thought I just was confident in my masculinity, only I didn't do anything that was particularly masculine.

As a kid, to man up was to take care of business. These days, it seems it might have been related to pony up which is to pay the ante, since it often is about paying bills. But I was taught this was expected of everyone who was an adult, and is in fact called adulting to make sure bills are paid and household chores are managed enough to keep the larder full, the dishes clean and the elements and pests out. (Sometimes adulting was calling the utility company and asking them to please wait since I don't have the money yet. It still counts.)

Also in my youth, we had Cold War notions of manhood, which was the capacity to have unthinkable levels of violent power that you never use in any untoward fashion. Nukes were the ur-example, and guns were the obvious domestic example, but the gun was one of a dozen power tools that were only to be used with full safety precautions for their intended purpose.

But now, these days, gun owners believe the second amendment to the Constitution of the United States gives them the right to shoot people they don't like, and our elected officials act like children on the floor of their respective parliamentary halls and Dick Cheney shot judge Harry Whittington, and Whittington apologized to Cheney because WTF?

So I'm enby: don't care. There are no characteristics or traits I can imagine one sex should have that the other sex shouldn't. I am the black hole that no-one would notice except for all the stars.