my name's jason but when we were kids my li'l sis pronounced it as "jahson" so it kinda' stuck with me...i put the "x" at the end to make it sound somehow cool just like the name of that big blade wielding horror flick character!
Heh, a childish name I thought of when I was 6, it pops into my mind so fast I dont even have to think to type it, so I just keep using it. I should probably get a new one though.
From when I was six me and my friends would play w/e games 6 year olds play outside and we renamed ourselves, and the names stuck. Now, we all use those names for our online usernames/screen names.