I decided to call myself Boltgreywing after the name of my electric bat character. I kind of need a username that I would identify with and so Bolt kind of stuck.
My username came from a Necromancer character that I played in original Everquest. And I liked the name so much that it has stayed with me for 25 years. I use it for everything.
Mine stands for Boss. My deeper meaning or whatever you want to call it is for me being my own boss. I also like the way it looks, reminds me of Bowser.