The thing that bothers me about the concept of gender fluidity is that (in my view anyways) it shows a warped understanding of the connection between gender and biological sex. How we perceive gender has a lot to do with what we expect culturally from each gender. Men are expected to be tough and like sports, and females are expected to be dainty and like flowers, etc... (obviously an incredibly simplified example, but my point still stands). Now the way I see it, the kinds of things you like and the kind of personalty you have doesn't really determine what your sex is. I can like sports, or I can like flowers, but in both instances I am still biologically male. I see no reason why I should have to 'become female' to enjoy feminine things, or why a girl should have to 'become male' to act in a manly manner.

Or maybe I'm just misunderstanding the concept. It never made much sense to me anyways, and I never bothered to learn because I am mentally stable and well adjusted and such concepts have no meaning for me.