I'm an IT man. I sit in front of computer screens with green text on a black background, all day, every day (because that contrast is the least headache-inducing). One of my biggest strengths is network engineering. In a nutshell, I build computer networks for a living.
In layman's terms, information is sent through computer networks in "packets". (look up packet-switched vs circuit-switched networks for a broader explanation).
When there's a problem with something I'm working on, I have a tendency to immediately want to instantly delve into the nuts&bolts of those information packets getting sent back&forth. To a layman, it can look intimidating. To my coworkers, I just look geeky. It's somewhat of a pretentious screen name, but it does fit me - when there's a problem, I'm the dude sitting there looking to the Matrix for a solution.