When asked to recall their earliest personal memories, most children and adults have virtually no recollection of their infancy or early childhood. This phenomenon is commonly referred to as childhood amnesia. The fate of our earliest memories has puzzled psychologists for over 50 years, particularly in light of the importance of early experience in human development. Empirical research has shown that infants can both learn and remember very early in development, making the ultimate fate of early memories even more mysterious. The theoretical explanation of childhood amnesia outlined here relies on age-related changes in encoding, retention, and retrieval that occur during infancy and early childhood. Data obtained using a host of different memory tasks support the conclusion that quantitative changes in these basic memory processes can account for the decline of childhood amnesia during the third or fourth year of life.