“[U]nderstanding how the brain reacts to stress or early trauma helps clarify how what has happened to us in the past shapes who we are, how we behave, and why we do the things we do.”

Winfrey clarifies the book’s underlying message: it endeavors to explain how trauma impacts the brain, and how this, in turn, plays a vital role in shaping who we are. Thus, it becomes important to constantly ask the question “What happened to you,” in trying to understand another person and their actions.

“[S]ince the brain is the part of us that allows us to think, feel, and act, whenever I’m trying to understand someone, I wonder about that person’s brain. Why did they do that? What would make them act that way? Something happened that influenced how their brain works.”

Perry, a child psychiatrist, discusses how he approaches his clients. Perry’s training and background is evident here: being a doctor, he has a grounding in biology and science, which leads him to apply this context in making sense of human behavior as well. Perry uses his clinical training and experience to draw understandable connections between biology and behavior throughout the book, particularly in the context of trauma. His expertise also helps explore one of the central themes of the book, The Biological Context of Trauma.

“As your brain starts to create the complex memories that store these connections, your personal catalog of experiences is being created. As we grow up, we are all trying to make sense of what’s happening around us. What does that sound mean? What does it mean when someone rubs my back? What does that expression on his face mean? What else happens when that scent is present?”

Perry explains how one’s early experiences and the memories they create can shape one’s entire worldview as they grow. Sensory inputs are the baby’s first window into the world, and as these sensory inputs—sounds, smells, sensations, and so on—are processed, feelings and experiences that are paired with these sensory inputs are registered, too.