The first 1,000 days of life, from conception to age two, are critical for a child’s physical, cognitive, and emotional development. Recent advances in preventive paediatrics highlight this period as crucial for fostering lifelong resilience. Early nutrition, responsive caregiving, and safe environments profoundly influence brain development and long-term health outcomes. Interventions during this phase include maternal health optimisation, breastfeeding support, timely immunisations, developmental screenings, and caregiver education. Tackling social factors like poverty, parental mental health, and healthcare access is equally vital. By focusing on early prevention and holistic support, paediatric care is shifting from disease treatment to long-term health promotion. Strengthening resilience in the first 1,000 days lays the foundation for healthier, more adaptable individuals throughout life.