In my late teens/early 20s I sometimes used to joke I was a gay man in a woman's body. I often think of this on trans threads, specifically when the question of "what is feeling like a woman?" arises.
Being an introspective type, I used to ponder why I felt, to some extent, like a man. I couldn't put my finger on it exactly, but there were two main things: The first was that I felt more like I suited the role of "camp gay male" when in a group - equally male and female friends but slightly an outsider to both, somehow, liking double entendre/innuendo type jokes (I remember thinking pantomime dame (!) was the epitome of acting roles, what a shame the men get to have the best part!)
The second thing was something to do with feeling more... I dunno, sturdy (I'm not large physically), and practical. Eg. out in town for the night I would wear a feminine, sexy outfit, but with Dr. Martens and a big hoody/jacket to keep me warm there and back (and for freezing smoke breaks when the law changed). Draping a jacket over a shivering impractically dressed woman made me feel "manly". 
Soooo a massive bunch of stereotypes, basically. But it manifested as a sort of vague internal sense that I still can't put into words. Can only explain it by saying "I felt like a man when I did x,y, and z".
I never for a moment considered I could be "trans" or doubted I was female. Because reality - hello, biological fact!