Let's see... I have some similarities and some differences from everybody.
QuoteI had three sisters, so I had no idea penises existed for the first decade or so of my life.
Same here, no knowledge of the male anatomy and yet I also tried to pee standing up. When I was about 14 I tried my hand at packing too, but only in the privacy of my room.
I hated dresses and hated going to church for this reason. I think I would have liked it better if I'd been able to wear what the boys did.
My first best friends were two boys.
I was a tomboy and wore loose T-shirts and home-made pants, actually. I would pick out cool fabrics from Walmart and my mom would make me shorts.

I wore these until I got into high school and the other kids were especially mean about my pants and my hairy legs that I refused to shave. Then I switched to men's jeans, because they fit better on my stick figure than women's jeans. I also wanted to be the male heroes in movies, (Yay, Luke Skywalker!

) when my sister and I played pretend with movie or book characters I was always a boy, and although I wasn't allowed to dress up for Halloween, I never would have considered dressing as a girl character.
Puberty was terrible. I didn't want what was happening and thought my body would eventually realize that and revert back, but it didn't. I also couldn't understand how the other girls could be remotely happy about what was going on. (It still seems impossible to me.)
I guess I'm different because I loved having long hair and I got very upset when my mom would cut it. I'm also a prude and I never had the urge to run around without my shirt on. I actually used to have nightmares about arriving at school without any clothes on, and even if I got top surgery (which I would LOVE) I think I would still feel too naked to go shirtless.

I've also been mistaken for a boy all my life; the most recent occurrence being last year. I was 18, my hair was long enough to sit on, and I wasn't doing anything to hide my (admittedly small) chest other than a snug sports bra and loose T-shirt. My mom gets indignant and corrects people, but I've always been secretly pleased.
Also, since I've always been boyish my family likes to tease me about how I'm actually a boy and how my mom has two sons instead of one. I don't think they have any idea... I want to tell them because I think it would make perfect sense, but I'm not sure how they'd take it, so I just enjoy the "teasing."