There is no one "trans narrative", and the one you often hear ("born into the wrong body" thing) is an exageration anyway. I am on educational panels, telling people about being trans. There may be 4-6 of us, and we all have a completely different story-- when we figured it out, how we felt about our bodies, etc.
I didn't so much hate my body, as felt I didn't belong in it. I lived most of my life outside of it, in a sense. I did NOT think I would grow up as an adult male, I pretty well knew I would not grow a penis, and so on.
I am actually pretty well happy to be a trans person, and have a little of each (I don't like that way of framing it, but have no idea how to do this in a few sentences). I know that there are other people here that see themselves as men (or women in other areas of the forum), and as having a birth defect, which I don't think of this as. I am saying all this to show that there really is NOT one way you can be transgender. You know what they say? If you know one transgender person, you know one transgender person.
--Jay