Analysis of Jimmy's character and decisions in Season 1
The entire first season is the story of a directionless man trying to find his way in life. Chronologically speaking, Jimmy starts out as a scammer who doesn't really have any idea of what to do with his life, despite the fact that in a moment of insight he admits that about all the scams do is earn enough for beer or pot money. This inevitably got him into one scrape too many with the law, and he had to be saved by big brother Chuck. So Jimmy totally changes his life, follows big brother's lead out to ABQ, starts working in big bro's law firm in the mailroom, while taking classes at night hoping to be a lawyer like Chuck and become part of the firm. When that doesn't work out for him he takes Chuck's advice to start doing public defender work. When that's being rough on him, he takes an offhand suggestion by Kim to go into elder law. This is a guy flailing every which way trying to find something that works for him.
Still, the whole time he is living in a self created prison, just as Marco said he would when he first left for ABQ. Because while Chuck may be all about the law, a code of integrity, and the ways laws intersect, Jimmy is about the performance, whether it's winning over a jury through charisma and personality or the way he plays a role in a con. And trying to model his whole life after Chuck isn't working for him, even before The Reveal about Chuck's true feelings about Jimmy. Jimmy trying to be Chuck in a courtroom, or day in and day out in a law firm, is a 180 from who he really is and what really gives him joy. So after he gets back in touch with that side of himself via his one week stint with Marco, when he looks at the future of forcing himself to be a Chuck clone in a fancy firm for who knows how long, he sees, despite being very lucrative financially, a type of drudgery and being caught in that bad fit of playing someone that he just isn't forever. Hence why he decides to take off at the end of season 1 and leave the serious law firm behind. For extra irony though, knowing the way that Breaking Bad ends, he winds up choosing not to go into one sort of Gilded Cage, only to wind up in another after a few years of having his fun as Saul.
