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Do it
(feddit.org)
For me Its quite simple. My brain decided it. Literally. The days I found out I'm trans, my brain would do this weird thing, where I could think about completely different stuff and suddenly my now chosen name would "fly" into my mental Field of View, like an asteroid in star wars or so. I told that name a close friend and 4 weeks later when we went to the club together I told him, that I will stick with it, because I didnt had a better idea (and it was the only name I really felt comfortable with).
I'm not sure I qualify for this (relevant username) but I do have two names I think about using if I ever crack my shell. One is just a name I always liked and one is part of an online pseudonym I used a long time (and that I still use sometimes) that has a totally different backstory, can be used kinda androgynously but is mostly used by women with one noticeable exception.
And no one is stopping anyone from choosing more than one name.