It's simple really. Back in my high school days, I wasn't exactly a popular guy. I really don't remember who made up the name "Jockess" or why it got applied to me.
One day my friends said "Ok, we've got a nickname for you, and now we're going to call you Jockess." I really didn't like it at first, but it grew on me and my friends would call and ask for "Jockess". My parents thought it was funny and they liked it. It grew on me, and I eventually adopted Jockess as my call sign. About then, I discovered the advent of computer BBS's and needed a "handle", a name to go by. So I adopted the handle of Jockess.
It's stuck with me ever since. What started as a unwanted nickname evolved into a description of me. It became my handle, and my nickname on IRC and ICQ. While it is funny and requires an explanation, it is something of a legacy.
To this day, my brother calls me Jockess. Sure confuses the heck out of people
when they see a 300+ guy being called "Jockess".