What is normal human behavior though? Is it some combination of things that's gonna end up being so rare that only so many people fall under it, and is it normal if it's so rare? Is it gonna be "what most/average people are", and if so, well then, isn't everybody gonna have something going on, and isn't that just normal then?

With how widespread it is, labeling, self-diagnosing, inquiring about yourself, is kind of normal human behavior. It is everywhere, and has been historically. Putting it like it's just 'labels for significant things' and then 'normal', and that these things would stand far enough apart to actually make a clear distinction without dismissing people in between is pretty much just wishful thinking. There's way too many things and even more combinations of then. It's gotten so complicated and convoluted only because it is that way. Wishing for a binary clarity in a complex world.