I can't remember much of my childhood at all, even though it's not been that long ago. I never really considered gender at all, there were only 3 of us in my year at primary school (all supposedly "girls") until I was seven when there were another pair of girls and three boys that joined us. Maybe that had something to with me getting depressed, because I remember it was one of my friends seventh birthday party where I refused to come down from a tree because there was no point me living so I might as well stay up there until I died, and I'd been fine until they joined. I first really started thinking about gender when I started puberty, and used to stand in front of the mirror every weekend and lift my arms above my head/out to the side to try and convince myself that I wasn't growing breasts. I actually thought I had breast cancer because that made more sense to me than getting breasts. I tried to ignore my period equally as much.
I don't think I ever told my parents that I was a boy, but whenever anyone asked me if I was going to have a "sex change" when I was older -- kids my age who noticed I was a complete tomboy obviously, not adults -- I would always say "No, but if I could have chosen I would have been a boy." I think there was part of me that was too ashamed to admit that I wanted a "sex change" even to myself, but it was never the flat out "no" it would have been if I really didn't want something like that. I didn't really know it was possible, and didn't just turn people into freaks. I still get asked if I'd have a "sex change" and I just say "no" and look pissed off while pooing myself encase they realise I'm not just an uber butch lesbian.
When I tried coming out to my parents before my dad said that there were more surprising things I could have said, so I think I outed myself through my actions even though I don't think I explicitly said it.