@Willow back in the dark ages, a bunch of my friends were in the Society for Creative Anachronism, and they managed to drag me in a little bit (it wasn't hard). When you go to a SCA event, you're usually in period character - it's basically a huge LARP in all but name. So I needed a character, and that character needed a name. Given my hair and general look and interests, Scottish or Irish was obvious, so I went into the depths of the college library and dug out a book of old Celtic names. Somewhere in there I found "Rowan" which it told me meant "little red one" or something like that, and I figured that would fit. That it was also a tree crossed my mind, and I kinda liked that, too, but of course I've never seen a rowan tree. I started using it at SCA, and also as a character in a group story we were writing on the BBS at the time. It fit me, quite well, and much better than the super annoyingly common name that I'd been given by my parents. Everyone started calling me that all the time, and by the time I left college, my given name was all but forgotten.

Turns out that it's an equally good name for many genders, and nearly 30 years later when I figured out a few things about my gender, my name was one thing that was still well and truly mine.