For my part, I'm a boy with a uncommonly hight amount of magic. It might be linked to the fact my mom used to be a battle magical-girl. She might still have been, if she wasn't forced to use all of her powers to protect me as a baby. Some of the patriarchal fuck-ass profited that my father wasn't home to try and coerce mom into participating in their experiment. Like dad was stronger than one of the strongest battle magical-girls around…
Because yes, mom was considered one of the most powerful magical-girls in her time. There was, and still is, far more stronger, but she was strong enough that she hadn't been able to change back into her normal form for quite a time. Must have been a shock for dad to see mom out of her magical-girl form, especially since magic make it hard for people to associate a magical-girl with her real self. (The stronger the magical-girl, the harder it is.) But they're still together, so I suppose everything worked for the better in the end.
Ether way, while some speculated that I might have absorbed part of her magic when she protected me, causing my hight level of magical energy (for a boy), other claim it's because mom gave birth to me in her magical form, a form I never saw. Since my powers never decreased, like it did for other boys my age, more and more scientist think the second explanation might be the right one.
As you might have supposed, in a world were everyone as at least a tiny bit of magic, everyone learn in school how to use magic, especially since, because of its reality-altering nature, the tiniest spark of magic can cause a street-wide catastrophe.
The thing is, class are formed depending on everyone magical potential. Because of it, I never had much boys in my class, the number of them diminishing every years. In fact, as I'm about to enter high-school, I know this time I'll be the only boy in my class for my practical lessons on magic. Everyone else will be girls. Most even magical-girls, albeit the weakest of them.
Well, still a more enviable place than being one of the rare almost-magicless girls. At least I'm just teased, were those poor girls are bullied for being, I quote "the magical ineptitude of a boy rolled in the weak body of a girl". Half the time their parent being at least enabler, if not outright participants, of their torment.