Any discussion on how we care for infants and toddlers must begin with the interests and needs of the children themselves. Therefore, this issue opens with an overview of the dramatic development that takes place during the first three years of life, which turns the dependent human newborn into a sophisticated three-year-old who walks, talks, solves problems, and manages relationships with adults and other children. This article explains the new understanding of brain development that has captured public attention in recent years, and links it to developments in infant behavior that are equally impressive and influential: the growth of the body (size and coordination), the growth of the mind (language and problem-solving abilities), and the growth of the person (emotional and social mastery). It emphasizes how much early experiences and relationships matter. The article highlights themes that resonate across these aspects of development: ◗ A drive to development is inborn, propelling the human infant toward learning and mastery. ◗ The opportunities for growth that enrich the early years also bring with them vulnerability to harm. ◗ The experiences that greet children in their human and physical surroundings can either enhance or inhibit the unfolding of their inborn potential. ◗ People (especially parents and other care-givers) are the essence of the infant's environment, and their protection, nurturing, and stimulation shape early development. The author envisions a society that stands beside the families and caregivers who nurture young children, equipping them with knowledge and resources, and surrounding them with supportive workplaces, welfare policies, and child care systems.