I think you guys've got it, but the thing that I'd add is that it's not really about her boyfriend at all. He's just one of the many signs that she's changed and now she's "a kind that isn't so much in demand". What the big message is that the Lips are all still kids and love messing around and imagining stuff and she used to be good mates with them and the stuff about Paul was where they used to just sit around and laugh about stuff. But now she's grown up and turned serious and got herself a boyfriend who likes cars, stereotypical male things, and doesn't have any time for her old life, and she's got herself a job and works 9-5 and so she hasn't got any time for her old "immature" life, so she's left the "vegetables" for the very generic and bland world of adulthood, instead.
I think you guys've got it, but the thing that I'd add is that it's not really about her boyfriend at all. He's just one of the many signs that she's changed and now she's "a kind that isn't so much in demand". What the big message is that the Lips are all still kids and love messing around and imagining stuff and she used to be good mates with them and the stuff about Paul was where they used to just sit around and laugh about stuff. But now she's grown up and turned serious and got herself a boyfriend who likes cars, stereotypical male things, and doesn't have any time for her old life, and she's got herself a job and works 9-5 and so she hasn't got any time for her old "immature" life, so she's left the "vegetables" for the very generic and bland world of adulthood, instead.