Before journalist Chelsea Conaboy gave birth, she anticipated the joy of holding her newborn, the endless dirty diapers, and the sleepless nights. What she didn't expect was how different she would feel - a shift in self, as deep as it was disorienting. Something was changing: her brain. New parents undergo major brain changes, driven by hormones and the deluge of stimuli a baby provides. These neurobiological changes help all parents - birthing or otherwise - adapt in those intense first days and prepare for a long period of learning how to meet their child's needs. Yet this science is mostly absent from the public conversation about parenthood. Conaboy delves into the neuroscience to reveal unexpected upsides, generations of scientific neglect, and a powerful new narrative of parenthood.