New Delhi, Oct. 22 -- On a humid afternoon in Mumbai, 68-year-old Usha Nair, a retired teacher sat with her daughter, staring blankly at the steaming cup of tea placed in front of her. "Did you make this?" she asked, confused, even though she had just watched her daughter pour it minutes earlier. Yet, an hour later, when a familiar bhajan drifted in from the neighbour's house, Usha's face lit up. She sang along, word for word, as if transported back to the temple courtyards of her childhood.This paradox is at the heart of Alzheimer's disease. Patients often lose hold of their present and forget meals, conversations, or recent visitors while retaining vivid, emotionally charged memories from decades ago. Why did a prayer or childhood festi...