For decades, researchers have documented a baffling phenomenon: young children spontaneously recalling detailed memories of lives they never lived—names, locations, events, and even deaths that seem to belong to someone else. These cases, often emerging between ages two and five and fading by age seven, challenge conventional understandings of memory, identity, and consciousness. Among the most compelling examples is James Leininger, an American boy who began having nightmares of a plane cras...