I tried for years to use what habits or activities I would involve myself in as a metric towards evaluating my gender identity. Being such a logical person and in computer science, I have always tried to use a sort of deductive reasoning and logic to apply to my understanding of myself and the world around me. It's very useful in some areas, but as far as identity, I have learned in the last couple years it is a very poor metric to evaluate yourself. The very definitions of what is "masculine" and "feminine" in activities, mannerisms, habits, etc, are highly subjective and continually changing. The notion that you can compartmentalize these things is insane at best. I have traveled abroad before, and norms in gender vary greatly throughout the world. Expression is most certainly different, and a number of variations are quite common. What is expected of males and females is highly variable on culture, and continually evolving.
Having come to very gradual terms that I am gender fluid, genderqueer, or bigender (still figuring that part out), has involved looking at something inside me far, far deeper than just outwardly things. This includes my body, my surroundings, my life choices, and so on. I still have yet to grasp what it is yet, but I do know that it has made my perspective on the world different since I have come to gradually embrace it. I'm actually grateful to a degree; it allows me to see new perspectives, and makes me WANT To experience different things and not limit myself to one particular way of living or being.