We're you thinking about your sex or gender at 7 years old ? No you weren't, and don't try and lie by saying you were.
No, not that I can recall. Indeed, were one to ask of what I was specifically thinking as a seven year old, I'd have to answer in terms of events I can remember from then and infer that they and things related to them were what I was thinking about.
- I got a telescope for my birthday that year, so I was thinking about the moon and the stars.
- I loved to read about nature and animals, and I recall asking my parents if we could go to Africa for Christmas to see zebras and lions and whatnot.
- I remember visiting my Southern relatives and hearing Granddaddy's tales about there being 'gators in the pond in front of the house and that being the reason he never could catch a big fish there. I thought I probably shouldn't go down to the pond by myself.
- I recall singing songs with the women who worked in my family's home. I thought I like singing and hanging out with them.
- I remember my aunt advising me to "never let the good be the enemy of the best."
- I remember watching television with Mother one evening and Daddy's walking into the room and heading straight for the restroom to "puke his brains out," whereupon Mother shuffled me out of the room and told me to go to bed. I was wondering why Daddy was sick.
- I remember playing all sorts of games -- tag, baseball, kickball, football, Monopoly, Life, croquet, badminton, checkers, duck-duck-goose, dominoes, etc. -- with my friends, parents, and others. I'm sure I was thinking about how to win.
- I asked Daddy to help me build a treehouse, which he did. So I thought about all sorts of things related to that task.
Most directly related to your remark, I recall that at naptime one day in the first grade, three other kids and I crawled under the beds and played "I'll show you mine if you show me yours." When I saw the girls', I thought, "What's up with that? How on Earth does that work? I'm sure glad I'm not a girl. What a nuisance that setup must be." Was sex and gender specifically on my mind? No, not in the precise and active sense of the transgender discussion broached in this line of discussion. It was nothing more than a precocious curiosity thing.
Given my first grade reaction to discovering "girl parts," there's no doubt in my mind that I definitely was not thinking I should have been born female. Indeed, I haven't ever thought the body parts I was born with are incongruous with those my brain thinks I should have been born with. Thus I'm hardly in a position to use my personal thoughts and experience as a basis for opining about or attesting to what transgender kids think about their own sex, or sex in general, at seven years old or at any any other age. I also wasn't a musical, math or other prodigy/savant at seven years old; thus also I have no idea what those kids think about.
At 7 years old, all we were thinking about is kid stuff...
Apparently, all seven year olds don't think only about "kid stuff." Perhaps, however, some seven year olds play "I'll show you mine if you show me yours" and think, "That's what I should have instead of what I got." I don't know, but it's probably not outside the realm of possible thoughts youngsters may have.