Of course a book called You Should Have Known is going to focus on perception—namely, how those perceptions clash with reality. The most obvious example is Grace's perception of Jonathan, who has been leading a double life for as long as she's known him. That said, her views on nearly every other character in the book—including herself—also undergo a serious transformation. For someone who once considered her perceptive abilities her superpower, Grace's reality checks throughout the novel bring her back down to the mortal realm.
While Grace appears to be a competent, insightful therapist, her perceptions of almost everyone in her personal life are highly skewed.
You Should Have Known challenges readers to reconsider their own perceptions as the story unfolds.
"Why do you look at the closeted husband in your patient's life and pay no attention to the murderous psychopath in your own?" —The Book of Grace 7:5
We admit that's not a direct quote, but the Bible verse that inspired it might as well be the motto of this book. Grace is a marriage therapist, but her own marriage is damaged beyond repair and she doesn't even realize it. Beyond that, she based her idea of a successful marriage on her parents, only to learn that they were also incredibly unhappy. If we could assign everyone in this book a default relationship status, it would be, "It's (seriously) complicated."
The thesis of Grace's book is that if you don't notice warning signs early in a relationship, you may choose the wrong partner, and your eventual unhappiness is unsurprising. Unfortunately, she failed to notice the warning signs in her own marriage, which simultaneously proves her thesis both right and wrong.
While Grace's attraction to Jonathan was intense and immediate, her relationship with Leo grows over time.
It's hard to say which of the Sachses is more familiar with reinvention. Jonathan completely reinvents himself when he goes to medical school, creating a new backstory in which he's the victim instead of the villain. His supervisor at the hospital even observes that Jonathan becomes a different person depending on who's in the room, putting up masks in a way that's fascinating to watch but must be exhausting. However, when Jonathan's "perfect husband" mask finally comes down, it's Grace who must reinvent a new life for herself and Henry, and she's surprised to realize it's easier than she expected.
In healthy relationships, both partners try to fulfill each other's needs, but Jonathan takes this to an extreme by creating a false persona for Grace to fall in love with.
It's not as difficult for Grace to leave NYC as she expected because her connections there are shallow. Finding a stronger community in Connecticut helps her and Henry start their new lives.
Before the whole disappearance/murder fiasco throws her into the deep end, Grace's life is in much shallower territory. While she and Jonathan are financially comfortable, she recognizes that they're nowhere near as wealthy as most of the parents at Henry's posh private school. The uber-rich families operate on a different playing field, one with toe-shortening surgeries, Birkin bags, and $25,000 summer camps. Grace often feels like she doesn't quite belong around her wealthier peers. Still, they're all Rearden parents, and Grace realizes that the only thing separating them from fellow Rearden mom/murder victim Malaga is their money.
Grace feels like an outsider among the high-rollers of Rearden, but she also considers herself "above" the frivolous, worldly things that are important to them.
Because Grace is so stuck on the idea that Henry's expensive private school is the "best of the best," she assumes that Henry's new public school will be horrible and the kids will be hillbillies. In reality, the public school is just as strong as Rearden academically—even stronger in some subjects—and Henry makes friends there easily.
Both Jonathan and Grace represent survival in different ways. As Jonathan's former boss points out, Jonathan is 100% focused on his own survival, which leads him to treat people like they're disposable if they're not helpful to him. Because his conscience is more twisted than the handmade scarf from his mistress wrapped around his neck, Jonathan also alters his personality to cast himself in the most favorable light depending on who else is around. On the opposite end of the spectrum, Grace feels like her own survival is at risk after Jonathan disappears, but she forces herself to keep moving forward for Henry's sake. Within a few short months, she's blasting "Since U Been Gone" and is not only surviving, but thriving in her new community.
Grace notes that Jonathan is like the dog in the Jack London story, concerned with its own survival while its master freezes to death.
Despite her husband disappearing after his mistress is murdered, it truly doesn't seem like Grace understands the severity of her situation until she learns that the police want to test Jonathan's DNA for a paternity test.
Attention is a double-edged sword in You Should Have Known. On one hand, attention is good when you're staying aware of potential roadblocks and warning signs in your relationships, at least in Grace's mind. She even suggested Attention Must Be Paid, an homage to Arthur Miller's Death of a Salesman, as an alternate title for her book. On the other hand, Grace hates how much attention the media gives to Malaga's murder—especially when the news breaks that her own husband is implicated. She up-ends her entire life to escape to the lake house with Henry, far away from the media's attention.
While the intense media scrutiny of Malaga's murder heightens tension in the book and gives Grace a reason to leave NYC, the news coverage also seems so unbelievable that it detracts from the story as a whole.
Interestingly, the quote Grace references from Death of a Salesman actually encourages a character to look past his father's flaws and see the good in him...which is pretty much the polar opposite of Grace's thesis.
Like onions, ogres, or Oreo cookies, the theme of isolation in You Should Have Known has quite a few layers. On the surface level, Grace recognizes she doesn't quite fit in with the Fortune 500 parents at Henry's school and doesn't have many real friends. Digging a little deeper, she realizes that Jonathan intentionally isolated her from his family and her old BFF Vita in order to control how much she knew about him. Of course, when she and Henry leave town, they flee to the lake house in the middle of nowhere and live in literal isolation for a while. Thankfully, by the end of the book, they're beginning to settle in and form friendships, while Jonathan is a fugitive somewhere in Brazil. Serves him right.
Jonathan systematically removes everyone who could tell Grace the truth about him. He tells her that his parents were horrible so she won't insist on meeting them, he competes with Vita for Grace's attention until Vita goes away, and he blames Grace for making it difficult to befriend his coworkers. One would think that a marriage therapist would have recognized these tricks, but Grace remains oblivious.
The physical isolation of the lake house is both a blessing and a curse. On one hand, it gives Grace some space to process her emotions, but it's also lonely, cold, and depressing, which can't be helpful.
The most obvious representation of growing up in You Should Have Known is Henry. We're told over and over again how handsome he's becoming, how tall he's getting, and how long his eyelashes are growing—it'd be pretty hard to miss the 872 times Grace pointed that last one out. Beyond that, he also grows up by becoming more responsible, more social, and more aware of the many sins of his father. On a more subtle level, Grace grows up, too. She releases the "giant Pause button" she pressed on her life the night she met Jonathan, finally leaves her childhood home behind, and starts creating a new life that's all her own.
Jonathan's seamless transition from "cheater" to "Dad" both times that Henry saw him with another woman made Henry think everything was normal, which kept him from telling Grace.
For Grace, leaving her lifelong residence is even harder than leaving her career, colleagues, and even her husband.