Among the oldest among us, a quiet mystery persists: some people in their 80s and 90s remember the world as vividly as those half their age. For nearly two decades, researchers assumed genetics might hold the key, but a landmark study of 142 so-called SuperAgers has now ruled out inherited Alzheimer's risk as the explanation. What protects these minds appears to lie not in the lottery of birth, but somewhere in the uncharted territory of how a life is lived.