Gravity Is the Thing by Jaclyn Moriarty

The same year Abigail begins receiving chapters from a mysterious self-help book, her brother disappears, never to be seen again. Gravity Is the Thing is a novel about how these two events affect Abigail and her choices for decades. The narrative is disjointed and fragmented, uniquely illustrating Abigail's thought processes but also mirroring the messiness of life, where there aren't tidy little resolutions and clear-cut sequences of events. "Causation is complex," Abigail, a former attorney, likes to say. But even that simple statement is challenged by another: "life is full of memories, stories, and facts, and we push our way through them ... and now and then, we pluck one, pull on the seam and make that responsible for everything. ... Which ... is wrong." It's only when Abigail realizes that causation may not matter at all, at least not in the way she thinks, that she can finally live her life free of the blame and self-doubt that has weighed her down. (See what I did there?)

The story is by turns funny and gut-wrenching and profound.  It's also resolutely grounded in real life, despite the self-help book's assertion that Abigail and her companions can learn to fly -- there's not a hint of magic realism here, as characters remind us repeatedly that humans cannot fly, ever.  Instead the novel finds magic in the relationships between the characters, in the small, ordinary events that can brighten a day or cause a major shift in understanding, in the coincidences that change everything, and the moments that free us.