Data point: I am physically (and I am figuring, genotypically) female but have never felt that I have an "internal feminine identity" of any kind.

For opposite values of sex and gender, the same goes for me. To the extent that I do conform to certain masculine stereotypes I don't view them as critical to my identity, just another semi-arbitrary socially constructed category that I belong to.

In my case, I had (often vastly) reduced exposure to most of the transmission vectors I would expect social gender identity memes to have. Out of curiousity, if it's not too personal, was your childhood particularly atypical in exposure to type of social environments/mass media/&c.?