There has been SO much written on what gender is from a theoretical or definitional standpoint so I’m going to skip the theory and go straight to my experience which is the only thing I’m qualified to speak on anyway.
Gender for me is less about presentation and outward appearance and more about a framework for explaining my experience of the behaviors and expectations around what it means to be a man vs a woman vs being me. We live in a binary world where regardless of what diversity there actually is in behaviors and ways of being for men and women, there are still expectations of what it is “supposed” to look like. Moving away from those expectations helps everyone in my opinion. But after a lot of thinking on it, I believe that even without binary expectations, my nonbinary gender would still exist as a way for me to explain just HOW different my experience is from the norm. Categories may feel restrictive to some people, but for me it is somewhat freeing to have a place where I fit.
My genderqueerness started as a mental scaffolding for me to explain and create structure around my experience of the world LONG before it resulted in any outward changes. As I gained more language around gender, that scaffolding grew and took shape. Without terminology, it was merely a swirling mass of confusion for me. That is part of why I am a big advocate of language that evolves and grows to meet the needs of a society rather than strict and static definitions. Without this new language, I think I would still feel lost in that void.
I believe that gender more about your own internal experience than it is about how you are externally perceived. Things like gender presentation and clothing can be helpful in signalling to people how you would like to be treated (not that it is frequently respected) but more often than not, especially in this unexplored middle area, I think it can be a barrier to people claiming their gender identities. I see many people in closed groups and discussions talking about how they don’t feel like they can “be nonbinary” if they don’t want to or can’t access an androgynous appearance. I know those feels and it held me back for a long time. So I’m here to say “to hell!” with that model of gender!
If genderqueer or agender or genderfluid or one of the numerous other new words to explain the uniqueness of nonbinary/trans experiences feels like it fits or explains things for you, then try it on. Take the time to think and feel about the description and explore the diversity of ways other people are using it. One person or site may be using a very narrow definition that you can’t see yourself in (like genderqueer for me at first) but I bet there are already people pushing and expanding the boundaries of that new category. And you could be next!
If man or woman describes your experience then great! Life may not be easy because both have a heavy burden of expectations, but at least you don’t have to fight to be recognized. If they don’t fit, then leave them behind and find the real you. You owe it to yourself to be authentic. Other people can fight you about it but rest secure in knowing that you alone are the expert on yourself.