Understanding how human memory processes collective trauma could revolutionize treatment approaches for PTSD and reshape our knowledge of how societies heal from devastating events. The decade-spanning 13-November research program has been systematically tracking how memories of the 2015 Paris attacks have evolved in survivors, witnesses, and the broader French population. This unprecedented longitudinal study examines not just what people remember, but how the emotional weight, narrative structure, and neurobiological encoding of traumatic memories shift across years. Researchers are documenting specific patterns in how initial shock transforms into processed experience, revealing distinct phases of memory consolidation that occur long after traditional therapeutic windows. The findings illuminate crucial differences between individual trauma processing and collective memory formation, with implications extending beyond terrorism to natural disasters, pandemics, and other mass traumatic events. Memory researchers have long theorized about the malleability of traumatic recall, but few studies have captured this transformation across such an extended timeframe with real-world trauma of this magnitude. The study's approach of following the same individuals through multiple assessment points provides rare insight into memory's dynamic nature rather than static snapshots. For longevity-focused adults, this research offers valuable perspective on how our brains adapt to and integrate difficult experiences over time. The findings suggest that memory processing continues far longer than previously understood, potentially informing more effective timing for therapeutic interventions and highlighting the brain's remarkable capacity for post-traumatic adaptation and resilience.