I just posted something in another thread that applies here.
Basically, when I came out to everyone I know, I "dumbed down" how I actually fee, and just stuck to the binary, so that it would 1. be easier for me to explain and 2. be easier for them to wrap their heads around.
I mentioned how people who are only able to see gender in a binary are like the flatlanders from this book I was supposed to read back in highschool. The flatlanders lived in a 2D world, and when taken to the 3D world, they could not see things for what they were, they could only see a 2D representation.
As you understand, gender is a spectrum, not a binary. I think the best way to help someone understand the spectrum is to give very general, and perhaps stereotypical examples.
i.e.
So dad, you ever notice how some guys seem really girly? ...Or how some women seem manly? Or how some guys are super manly, and some women are super girly? And some people you can't tell if they are a man or a woman. From my experience, gender identification and expression isn't a guy/girl or black/white thing.... it's more of a spectrum, like the rainbow! Sure, we identify a few different colors, but in reality, there's infinite hues, many of which our eyes can not perceive. Not only is it possible for a woman to be super manly, but it is possible for someone to be 'fluid', where they identify/express as a manly man at times, and at other times, a girly girl. Or maybe certain aspects of someone are manly, but other aspects are girly. No matter what, it is still one person.
This is how I feel. I do not like being in a male body, that is for sure! But I do not consider my soul male or female, it is simply me. I hope this helps you understand me better. Gender is, after all, a social construct. There are even societies on this planet right now that have more than 2 genders! There was a time when much of the world thought the planet was flat, and that we were the center of it all. Perhaps one day we'll look back at these days and think, "there was a time when much of the world thought gender was simply male/female". I hope this helps you better understand how I feel