One of my favorite books was "On the Road," by Jack Kerouac - a 1950's precursor to Hunter S. Thompson. It's about being a free spirit and loving life.
First one that popped into my head that wasn't already taken, and I ran through quite a few. Kind of cool, a little mysterious, fantasy theme, magical, not too dorky. Liked it enough to stick with it and not change it. Even got a few positive comments and questions from some providers over the years about it.
Actually, couldn't think of anything better at the time, and too lazy to change it.
When I was a kid, boys often went to the river and swam nekkid. Except for the kid with the biggest package, who walked back and forth along the bank of the river, just showin' off. He was called the Bank Walker.
I decided to use that handle, even though it arguable is false advertising in my case.
Mine is plainly where I live and man. I would have used my normal one which is much more creative but for this to better hide my identity I picked something completely different that I have never used before.