New Delhi, June 1 -- Kartik Parija prides himself on his elephantine memory, yet lately, names have begun to slip away. "I've had moments when I reconnect with someone from the pre-internet days, vividly recall our shared history but momentarily blank on their name," says the 49-year-old entrepreneur from Bengaluru. He recalls awkwardly steering such conversations without naming the person, while his mind scrambles to retrieve that "fundamental piece of personal connection". This lapse has emerged only in the past three years, he says. "It feels profoundly strange, like the fuzzy confusion after pulling an all-nighter before an exam."

Don't chalk it up to age. Screenwriter Shoaib Zulfi Nazeer has noticed this since his mid-20s. "Back in ...