Born in 2155, Jeff's upbringing and career have been colored by his health. Joker has a moderate to severe case of Vrolik syndrome, which causes extreme brittleness in the bones; he was born with severe fractures to his legs and even with modern medicine he finds walking nearly impossible, relying on crutches and leg braces.
Joker spent his early life on Arcturus Station because of his mother's job there as a civilian contractor, and grew up around ships. When he was old enough to enlist, he joined the Alliance Navy. He got his nickname from his flight school instructor, due to the fact that he rarely smiled — he was working too hard. By the end of his training, however, Joker surpassed the other students and even his instructors. "They all got their asses kicked by the sickly kid with the creaky little legs. One guess who was smiling at graduation." When the Normandy was commissioned, Joker was chosen as her pilot.
Pilot of the Normandy
The Normandy SR-1 starship was a joint collaboration between two powerful military forces: the human Systems Alliance and the turian Hierarchy, with each side bringing their respective skills at technology and engineering to the job. A prototype stealth-reconnaissance frigate, the Normandy was faster than any other ship in the Alliance navy, and equipped with an advanced stealth drive for missions into volatile regions of space like the Terminus Systems.
Upon its completion, the Hierarchy sent a top-ranking official called General Invectus to inspect the ship. Invectus arrives at Arcturus Station on a shuttle piloted by Joker, who voices his admiration for the Normandy and wishes he could be its pilot. Invectus tells him not to get his hopes up, because the odds of the Hierarchy's most advanced starship being handed over to a cripple are negligible.
While Invectus discusses details with Admiral Anderson and Captain Dillard, they get a distress call from the Normandy's crew, informing them that they've been hijacked and that the pilot has locked himself in the cockpit and sealed the kinetic barriers. However, Dillard is informed that the Normandy wasn't breaking their flight plan, sticking to the path they have already charted, leading Anderson to wonder if it's a malfunction. Dillard tells him that it isn't likely as the pilot can override the locks from within the cockpit.
Joker then comes in over the comms, telling them not to worry since the Normandy was in good hands, how he read the manifest, memorized the obstacle course, and that he'll "drop her off when he's done". One of the members of the patrol comes in, saying that he has a lock on the Normandy. He's told to bring down the Normandy in one piece. However, the patrol proves ineffective at stopping the Normandy, Joker being able to evade all their shots. Anderson wants to know who's piloting, and Joker tells him. Dillard tells Invectus that they have the situation under control, to which the turian derisively replies "Obviously."
Soon, Joker returns the Normandy back to the station, gushing about how amazing the ship is, believing himself to be in love. Anderson tells him that he'd have to write his love letters from prison, demanding to know what Joker was thinking. Joker tells him that while he's the most qualified pilot on the station, the moment people see him on his crutches he's no longer considered capable of piloting a ship. He goes on to say that he was born to fly the Normandy, and that the only chance he'd get to do that was to steal it. Dillard angrily tells him to tell all this to the court-martial judge, and that he was going to be locked up for a very long time.
Invectus tells him to wait, pointing out that while Joker can barely walk, he was able to run circles around their security protocols, and that he was able to keep his cool and adjust to unexpected conditions while under fire, all the while being able to beat their trials with spare time. He goes on to say that Joker is exactly the kind of man the Hierarchy would want piloting the Normandy, and that in the interest of continued turian-human relations, he strongly suggested that Anderson and Dillard listen to him.
Anderson agrees, but says that while Joker would have to be punished for what he did, he wouldn't trust the Normandy to anyone else. Joker is elated at the news, unable to believe that stealing the Normandy actually worked out well for him.