A nickname a co-worker gave me way back in '92 when I sold PC's wholesale to mom-n-pop computer stores in the metro area.
When going over specs of the PC's with clients, I said "dual floppies", or "dual 5.1.4 & 3 1/2 floppies" etc, and my co-worker thought it was funny.
The AJ part came in because he assumed that everyone with the first name of "Andrew" had the middle name of Jackson after the president. So I became "AJ Dual" in our inter-office banter.
I used to post under my name like some others, however, my last name is your typical SE WI/Milwaukee Polish "Alphabet soup" to most people, so I picked that as it was the only given nickname I could recall that wasn't completely nonsensical or obscene.
AJ Dual kind of brings up subconscious connotations of "Dueling" or perhaps a gunfighter with a two-gun "dual" rig I suppose, so I've stuck with it.