One of my lifelong loves has been playing guitar. There really is nothing in the world like it and if I could make a living doing nothing but playing my guitar, I damn sure would. So there's the "Guitar" part of it.
The "Cozmo" part has a story: July 4, 1997. My Kiss tribute band, Cold Gin was playing a gig at the Brokedown Palace in Washburn, WI. We're sitting in the upstairs apartment, overlooking Chequamegon Bay (a small inlet of Lake Superior), putting on our makeup for the show. Now the bass player, who'd formed the band many years prior had the same name as me. Since he'd been in the band longer, it was decided that I needed a nickname to cut down on confusion.
They liked to razz me about the fact that I was always a little bit of a nerd, so they suggested Newman (a la Alfred E. Newman). Then they all said "Nah, people will confuse that for Newman from Seinfeld". Coincidentally, at the time, I'd dyed my hair black to blend in with the Ace Frehley wig I wore for gigs. I'd also started growing it out, so it was constantly unruly and difficult to manage. Given the "Nah, they'll think Newman from Seinfeld" idea and my black, unruly hair, our singer mentioned about how my hair looked like Kramer's. Kramer's first name is Cozmo. Voila.