Third Life Jimmy fascinates me because I truly feel like he was not at all satisfied with cottagecore safety.
This isn't something unique to Third Life. While Jimmy falls into mundane arrangements just fine, he can be awfully restless. Jimmy often feels the need to prove something, to be more than the role he's often slated into. There are a number of times throughout the series where Jimmy has something going for him, something that's..fine, but that isn't enough, because he wants to be on the frontlines, because he doesn't want to sit still playing things safe.
During Third Life, Scott wants peace. He wants to build their cute little base and live off steak from their cows. He wants to avoid conflict and stay alive as long as possible. Scott's happy like that, happy with their life, happy with Jimmy, and with staying out of danger and conflict for the most part.
Jimmy, however, can't stay away. He dies participating in Dare to Flare, tries to disarm a tnt minecart outside of Dogwarts and gets himself killed in the process, burns the Dogwarts banner and makes an enemy out of them. Scott asks him repeatedly to stop being so reckless, to think rationally, but Jimmy is restless and bold and has something to prove. Jimmy believes he's capable of fighting and winning, and he wishes Scott could believe in him too! Jimmy makes it clear that he finds it cowardly and/or naive, how Scott keeps trying to appease violent individuals in the name of peace (or maybe scott just doesn't believe jimmy can protect him, which may be even worse)
Part of Jimmy's recklessness and anger is a genuine desire to protect Scott and the life they built together. Jimmy doesn't trust Dogwarts (he hardly trusts scar and grian either, to be frank) and he knows that getting caught up with them is a recipe for disaster. Jimmy sees Martyn and Ren as snakes, and he genuinely believes something terrible will happen if they just bend to their whims.
But I also get the impression that Jimmy felt like Scott was..holding him back? Jimmy cared about Scott, of course. Scott was..great. But I fully believe Jimmy had something to prove, and he clearly resented Scott to an extent. Because Scott was caught up in keeping them both safe, keeping them both alive, staying out of the fight. Scott never could understand why Jimmy would run through flowing lava, or step onto a live bomb, or go to war to prove some kind of point. Scott could never really see that Jimmy wanted more than poppies and cakes.
So Jimmy pulls Scott into a war, halfway to protect them and halfway just to prove he can, and Scott follows him, because all Scott really wanted was him. Jimmy dies in the first fight, fails to prove anything, fails to satiate the restless fire he had inside, meanwhile Scott is left in the aftermath, left to go through the rest of the season in a "daze" as the other players described, left to die miserable and alone shortly later. And we have, in every season since then, Jimmy continuing to chase more, continuing to run forward in an attempt to prove he's more than the role he's been cast in, because Jimmy insatiably wants for so much. And Scott..lingers, every time he sets eyes on a red flower. Because that's, tragically, inconsolably, who they both are.
