My birth name was Carley Ann (Lastname), and because I'm pathologically indecisive it took me AGES to pick a name. I initially rejected "Carl" because it seemed like such a plain, boring name to me at the time. Also I didn't like the idea of just taking the male version of my birth name.
So went through lists and lists and lists. I tried with Charlie but everybody else vehemently rejected that for me. Everyone. My mother didn't pick a name until I she knew my assigned gender and therefore had no possible boy names to give me. At the time she was also struggling massively with my transition and ignored my repeated requests for suggestions until I couldn't stand using my old name anymore. My Dad was supportive but seemed at a loss for suggestions. I tried Liam for a while, but it just wouldn't stick and it felt forced.
My Love couldn't stand callng me by a girl's name though, so she called me Carl (or usually "Carls") as a nickname. It enabled her to call me by my preferred name around family I wasn't out to, because they just assumed it actually was a nickname.
Then weirdly, somehow it grew on me. I fought it for a while and tried to find something both suitable and more unique but I guess I discovered that my name didn't have to be super unique, it just had to fit. I was hoping that I would have some super revelation and just know that this name was awesome and perfect for me. But I didn't happen that way (and sometimes I admit that still bugs me a little.) I just kind of slowly took on this one.
I never wanted to change my last name, I liked the family attachment even thought it's long and annoying to write. I wanted Lloyd as my middle name originally because me and my grandfather were super close and he was my hero as a kid. But one of my brothers already has that middle name and I felt that would be kind of weird. So I decided that I would ideally like some sort of family related name, hopefully from my Dad's side, and preferably keep my initials. After finally getting up the guts to ask my family for suggestions again, I told my dad my thoughts and he said "Well, your great grandfather's name was Arthur."
So last year I legally became Carl Arthur.