My Current username is an interesting story actually.
For a while I'd take on usernames of anime characters that were my favorites.
Three times I took on the names of Digimon like Calumon, Justimon, and Raidramon. My favorite show was indeed Digimon. :3
After being somewhat tired of Digimon names, I decided to take on a unique username. Thus the Username Pachy was born. I had a friend right here on PC who was going by a variant of the username Pachirisu. The variance was merely a few decorative unicode symbols before and after the name. All the same, this was about the time when I fell in love with the pokemon Pachirisu.
Because all decent variances of the username Pachirisu were taken, I had to do a bit of improvisation.
I shortened the word Pachirisu to 'Pachi' Somehow, this didn't sound right to me. The name sounded far too feminine when it ended with an 'i', and I was already somewhat confusing people and being mistaken for a girl because of my personality. So I settled on the letter 'y' which sounds just about the same and when it's at the end of a name, it's gender neutral. And so, "Pachy" was born.
All of my friends loved this new username, and I began widely adopting it elsewhere.
Then I evolved into loving an anime called Mahou Sensei Negima! From that series, I fell in love with a silent, and very minor character named Zazie Rainyday. :3 She represented so much of my personality I took on that name. From this very username I did adopt my LiveJournal username, Zazie Lavender. :33
Of course my friends soon lamented the loss of my username "Pachy". Try as I might, to get the name "Zazie Rainyday" or it's shortened "Zazie" to catch on failed miserably. By this time, everyone knew me as "Pachy" no matter what I choose to call myself. And so I switched back to "Pachy" because the name stuck on me.
Naturally more time passes, I got tired of "Pachy" again. Of course, at that time...Sentence style nicknames like "Careful with that axe, Pichu" and many others had caught on and were in style. Naturally, I sought to dream up a sentence which suited my more friendly and artistic side. And so the username "Paint me Pretty, Smeargle" was born. The entire time I had this name, people were indeed content to call me Smeargle, which I enjoyed. But no matter how much I might try to avoid it, Everyone knew that I was "Pachy", and while they never called me "Pachy" to my face, They always referred to me under that name amongst themselves.
And so, when the announcement went out that PC would no longer take username changes, I thought: "To heck with all this username changing" and changed back to Pachy. Besides, I'd already been awarded the Identity Issues emblem for changing my username so much. XD
And so, this is the story of my username. :3