A: In some ways, I wish I were more like him. He was so much more brilliant than I am, so much more of a performer, a much better writer. The things we have in common that I owe to him is a fearlessness, a demon-chasing quality that he actually didn’t have as much as I have. One pivotal moment in the movie is when the kids gang up on Irma (Rex’s mother, who sexually molested both Brian and Rex), to beat on her head. She was the personification of my father’s demons, but he couldn’t do that himself. It freaked him out that his kids could.
Here, we understand that her book was meaningful to many, but it’s not terribly engaging as told. We know she survived the ordeal, so there’s no suspense, and it’s hard to be invested in whether or not she reconciles with Rex before his death. Cretton captures the incidents of Walls’ childhood (too many of them, to be honest, as the film really ought to be half an hour shorter), but struggles to connect them to the grown woman Larson plays in the present. Here is a successful New York gossip columnist whose own story was juicier than practically any she uncovered in her day job, and yet, despite its running time, it offers at best a fragmented portrait of how she was personally shaped by having a father as unique as Rex Walls.
The Glass Castle also shows how Jeanette assumes a motherly, caretaking role early in her life. Neither her drunken father nor her flighty mother is a consistently good parent, so Jeanette discharges those duties. She cooks (at one point catching her pajamas on fire and ending up hospitalized), strives to protect her siblings and takes care of both parents. Near the end of his life, Rex acknowledges the toll his addiction took on Jeanette: "No little girl should ever have to carry her daddy on her back." Rex praises her for being "beautiful," "smart" and "strong." And he reveals a scrapbook he's secretly kept: "It's every story you've written since eighth grade," he tells Jeanette, who's now a magazine writer.