I have more of a problem using the word cis to define myself than straight because I don't have any conflict with my heterosexuality whereas my identification with femininity is much more complicated, inseparable from my immediate family context, and the wider one of sexism and misogyny.
I remember some difficulties growing up, though not so much that it was ever debilitating, was much more consciously identified with my dad than with my right-wing 'female' hating mother. I wanted to be a boy when I was about 8, refused to wear a skirt for school, I remember pretending to be sick one day when the only pair of trousers that were clean were some horrible brown ones (1970s) and the alternative was a skirt, being the only girl in jeans on the end of a row of long-skirted girls in our class country dancing show, wrote my name as a boys name in my books. Obviously I wasn't as smart as a boy and of course I was crap at maths and I thought being a girl was a bit shit really. But I don't think I ever felt that I was 'really' a boy I just really, really wanted to be one and tried to magic myself into being one by wanting it so much. It didn't work and after a while I accepted that I was a girl, but not without some feeling of being a fake, a feeling that has got less as I age, especially since pregnancy and birthing and feeding my children, but hasn't totally disappeared.
I was going to post something more political than personal, about continuums rather than binaries, but it came out like this. I'm sure this kind of experience isn't uncommon.