We often think of babyhood and old age as opposite ends of life’s spectrum. Yet science shows they are deeply connected. The foundations of our mental and physical health are laid long before we can speak, shaping not only how we live, but how we age. In 1,001 Days, acclaimed psychotherapist and author Sue Gerhardt explores the crucial―and frequently overlooked―early-life factors that influence lifelong health. Drawing on the latest research in medicine, neuroscience, and psychobiology, she reveals how many of today’s most widespread conditions, including type 2 diabetes, cardiovascular disease, depression, and dementia, can be traced back to experiences before and shortly after birth. Gerhardt challenges dominant political and cultural narratives that frame illness primarily as the result of poor “lifestyle choices.” Instead, she shows how early caregiving, stress, and social conditions shape our biology in ways that persist across decades. Her findings have profound implications for how we think about prevention, screening, treatment, and public health policy. There is no simple cause-and-effect formula for health outcomes. But by understanding how early childhood continues to influence the body and mind, 1,001 Days empowers readers to rethink illness, seek appropriate support, and advocate for systems that prioritize early intervention and care. This is a vital, eye-opening book that has the potential to transform how we approach health across the lifespan.