Once upon a time there was a little baby who was misidentified as a boy. She grew up with ADD and a family much like many others. She struggled through high school a little, but then they put her on medication and her situation got better. She got her degree in comp sci, got a job admistrating databases, and moved out.
It was only about a year later that she figured out she wasn't a boy. But it wasn't a huge deal, honestly. Her family had opinions, sure, but she was making a very nice salary and didn't have to listen to them anymore.
Gradually, she blossomed a bit. She'd never had relationships in high school; turns out that was because she wasn't interested in being the man in a relationship. Lesbians, however, were perfectly fine. A long-term partner eluded her for now, but she was getting the hang of things, yeah? This socializing thing wasn't so hard.
Sure, she had a few problems in her life. It was hard to manage dating and work and her ADD all at once, not even mentioning the hobby writing she kept trying to do on the side. And the hormones weren't working quite as well as she had hoped. But she still felt... confident. Attractive, at least in principle, even if sometimes she still got blushy at close attention.
The dreams didn't seem all that weird. Dreams of a college full of attractive women were more than welcome, and the gardens she dreamt of seemed calm and peaceful. Only the water-filled dreams ever scared her; she dreamt once of her heart being torn out by a beautiful woman with fins for hands, and that was... not entirely a bad dream, let's put it that way.
And then one day she woke up on a small ridge of black basalt in the middle of the ocean, with no other land in sight on the horizon.