it doesn't make sense to claim, as many do, that Lila stopped studying because she didn't get to go past fifth grade. looking carefully at the timeline of the first novel, she continued to read and educate herself for years after she was pulled out of school. until around age 13, she was checking out and reading multiple books a week, and she was not only keeping up with Lenu in middle school, but outpacing her. no matter what happened to her--her father's violence, Maestra Oliviero's cruelty--she kept studying.
my point isn't to say, oh, if Lila had bootstrapped hard enough, she would have made it. Lila herself seems to express this view at times, but I don't know if it's as simple as her being constitutionally incapable. yes Lila is ruled by her fleeting passions, yes she's too afraid to ever leave the world she grew up in, but that doesn't mean she had to quit study. again, she continued to read even after she stopped being encouraged to by anyone in her life.
so what was the defining moment that changed her priorities? the series makes it clear: Lila stopped reading after her first episode of dissolving margins. to Lila it was like the bottom fell out from under her, and all she could think to do was to try and keep things from getting worse. she thought, I can't maximize my ego anymore, it's contributing to this horror around me. Rino is going bad because I put all these thoughts in his head, but success to him means being like the Solaras. the focus of that episode was her brother, the person whom she had loved most until that moment, who she was afraid to lose. and she was right. reality, the events that followed, supported the worldview she experienced during psychosis. she was in danger of losing of brother. the world really could fall apart. and people, places, time periods, all so-called "individuals" were in truth not discrete entities, but beings with permeable membranes, oozing into one another.
from that moment on, at least in the way I see it, Lila put all her energies into trying to prevent disaster. she was not successful. she didn't know how to hold things together. the degree of terror she went through was too much for her, and she had no one she could ask for help, because no one else would have been able to understand. even decades later when Lila finally opens up to Lenu, Lenu doesn't get it on an emotional level. maybe she grasps her meaning to some degree, but feelings wise, she does not join Lila in her terror, she sympathizes but doesn't empathize. it's only we as readers, with the whole series and all its many philosophical implications in mind, who can do that for Lila: try to understand what she went through and why she was so scared.
I want to end this post by pointing out that Lila actually never stopped learning her whole life. there are periods when she apparently doesn't study, but also periods when she studies a lot. for instance, she learns from Pasquale and others as much as she can about corruption in the neighborhood after that fateful dance. she learns a lot about motherhood and childhood intellectual development during her first pregnancy. she of course studies with Enzo. in the final book, she becomes an expert on all of Naples and uses what she knows to create dazzling, nonlinear stories for Imma. reading those chapters, I found the origin of Lenu's mistake in imagining that Lila would write a novel. Lila didn't need to "make something of herself," she already was someone. her life didn't need to be justified by fame or a concrete creative output. no, Lila was creativity itself. why should her trips with Imma around the city, teaching her all about it, not be considered Lila's great masterwork? she doesn't live life through screens, never did, she lives in the here and now, working, exciting, creating.