Simply put, my genetic sex sux.
Really, it's the hair that bothers me the most. I shave my arms, legs, chest, face... It's time-consuming, and I keep cutting myself!
I'm relatively okay shaving my legs; it's not unusual in the least for girls to do that- same with armpits, and since I usually wear pants and a shirt, I'm not foced to see it that much. But when I do have to see it, like in the shower, it bothers me a lot.
I shave my arms every day so I can wear short sleeves (until I started shaving, I had to wear long sleeves, like a sweater, regardless of how hot it was), but I'll frequently find a patch of hair (usually on the knuckles or near the wrist) that I missed. Then I'll kick myself, but put it out of my mind and get on with my day. The fact that I can't get rid of my beard shadow (is that what it's called?) forces me to look away from any reflective surfaces unless I cover my face first.
I don't mind my genitals quite so much, partly because I don't spend a lot of time looking at them. Unless I'm in the shower, in which case I try not to look. In reality, I don't mind the penis- I don't like it, but it doesn't drive me mad the way my testicles do; I absolutely despise them, even just the word makes me cringe.
I'm boyish enough in nature that I don't mind being raised a boy the way some of you might, but do hate not being able to relate to girls biologically- whenever I hear an anecdote about a girl's period, I feel like I'm supposed to be able to relate, and it frustrates me that I can't.
Most days I can overlook my sex- I've spent my whole life trying to overlook my various physical defects- but I can usually put it out of my mind and just focus on how I feel- until I pass a mirror.