Not jealous. Vindictive. She's telling stories of all of the awful things he did when they were together. He owns up to them tells his new girlfriend he isn't the same person he was back then. explains that he was living a life he didn't want but didn't know how to make the change or in what direction. he was living his life as if he was just a spectator and he fell asleep during the film. he wasn't in control Then he met her and it's as if the old person had been erased. So much so that it's as if you reprogrammed "the character set" of a computer. He apologized for those mistakes in the past but maybe he isn't sorry because they shaped him into who he is now but how do you reconcile it with who you are now and incorporate the shadow? He calls the ex on her bs. Points out only reason she's bringing it up is because misery loves company. A narrative of my 2019 that's the thing about great songs everyone thinks it's about them.