This article addresses aspects of memory as they emerge in clinical work with children who are fostered and adopted. Based on Bion's model of interactive development and thinking, and on the neurobiological and neuropsychological work of Perry and Shore, emphasis is placed on a definition of traumatic experience as derived from when the child finds himself alone and unable to process those experiences for himself. The cumulative trauma of the lack of maternal containment is cited as relevant to thinking about the impact of trauma on adopted children. Clinical examples are offered as illustrations.