Joe comes from Tarra, a world with early 20th century technology. Other planets have significantly higher technology, but the infrastructure to build this technology isn't available on Tarra. The average Tarran lives a life pretty much we do. In Joe's universe, magic doesn't seem to exist. Psionics are rare on Tarra, and fairly common elsewhere in the galaxy.
Growing up, Joe did well academically and was extensively trained in computers and chemistry. Tarra is a primitive world and it never really invents anything "new". There is however a significant demand for figuring out ways to produce "obsolete" galactic technology with local technology. Joe is an expert in "reinventing" tech and figuring out ways to produce stuff without the replicators and nanotech normally used to make them.
Joe's last employer was an explosives company. Trying to rediscover explosives was an "interesting" job. The reinvented explosives never worked quite as well as the original did and Joe became quite expert in determining how to best use explosives. Joe has learned that being distracted from the task at hand is a bit dangerous and he can be oblivious to everything but his current problem.
One of the few things that Tarra gets from the the rest of the galaxy are highly advanced (for Tarra) VR games. Joe loves these games and is an expert in manipulating the computer systems that run them. Joe plays a wide variety of games from fantasy to historical drama. The imported historical drama's give Joe a pretty good understanding of offworld weapons and tactics. Since the games are based on historical (off planet) events, the experience they provided is quite helpful to Joe in places like Station 6. The fantasy games are pure fiction (magic isn't real), but Joe has used them to learn to adapt to the rules of any game.
Joe has learned a lot about small group tactics and has aquired some skill with missile weapons from playing games. Joe has also learned that he is just as bad with melee weapons in the games as he is in real life. This doesn't seem to be much of a problem to him - He makes sure he has a gun, bow, grenades or traps between him and a mob. Joe has learned that death is a bit painful, and that it may incur an XP penalty, but it's not that big of a deal.
Recently, Joe found himself in Wizardscape. He's pretty sure it is just another game or set of games. Wizardscape is a bit strange though - Joe doesn't remember entering the game and there isn't any obvious way to leave. This doesn't bother Joe much - he's having a lot of fun.
