I was recently commenting with an interested cis-gender man about what it is to be trans. I came up with the following analogy that I think is helpful:
There is indeed a spectrum within each person, and it is very often fluid. I like to illustrate it using sherbet and sprinkles; the sherbet is inner identity and sprinkles are outer expression of it:
So-called “manly men and girly girls” are like blue sherbet with blue sprinkles and pink sherbet with pink sprinkles. Over the larger course of humanity, the sherbets are mostly blue for guys with a variation of pink sprinkles (girly men having a LOT of sprinkles) and pink for gals with blue sprinkles (tomboy and tough gals having a LOT of blue sprinkles). For trans people, the bowl is filled with a blend of sherbet and sprinkles. In my case, my sherbet and sprinkles are mostly pink, but there is still a lot of blue, with the blue evaporating away to make room for the pink. I truly don’t know what the final mix will be. For others, that mix is very static, just like “The Rock of Gibraltar.” :-)
And then there are those who just don’t do sherbet or sprinkles — I liken them to rocky road ice-cream. They conform to nothing and will not have the same mix of gender identity or expression any given day, month, or year. They would easily also define as the “Q” in LGBTQ, and probably grouse that someone is still trying to bin them. :-D
Understanding this inner fluidity is a huge step for trans people understanding themselves, and for others understanding who we are.