a lot of dysphoria might be related to hormone receptors in the brain, and internal body map. wrong hormone levels will make you feel miserable, and wrong body parts will make you feel miserable. there are disorders that will make people cut off a leg or other limb, probably because it isn't internalized properly in the brain, because the people doing it are completely sane apart from not identifying with that one limb. there are also people born with too few fingers, lost their arm, and suddenly got phantom sensations of a fully developed hand with five fingers.
some times, what the brain thinks you should have, and how the body turns out, just aren't the same. the result is misery and a need to change. but it has nothing to do with how much you like pink dresses.
->-bleeped-<- is a disorder, in the sense that something is out of order. but it's not a mental disorder, there is something rather physical that is wrong with the body, according to your brain, on a level that is way deeper than your everyday thought patterns. some might insist the wrong is in the brain, but... the body can be changed a whole lot, but the brain can't, so i really don't see any reason why people shouldn't fix their body so the brain can recognize it as "right". i don't even find it weird that a man, who's a man in every traditional sense of the word, might want a vagina instead of a penis. or if a girl wants a male body.
the trans spectrum is probably more 3d than 2d. at least it's most certainly not just a line between ultimate male and female, where you find your place somewhere in between. finding the right mix of hormones and/or body parts can be anything from relatively easy to almost completely impossible.
just some odd thoughts.
and just to add some more odd thoughts. did you ever wonder a whole lot about how you might be a monkey, but your very human habits made you think that maybe you're not a monkey after all? cis people usually don't wonder if they're trans, just like humans usually don't wonder if they're actually some other species. unless they were raised by monkeys and suddenly realized they were human upon meeting one, but that's just a fictional work, i think. i do wonder about kids raised by wolves though.