India, Dec. 31 -- One Saturday morning, a couple of years before the Covid-19 pandemic emerged, I was at the Nehru Memorial Museum and Library in Delhi, searching through old records. Before me, on the microfilm reader, flickered pages from a newspaper published in Bombay in the early twentieth century.

At the next table sat a gentleman in his fifties, Mr R. He held a senior post in "Prasar Bharati" and had decided to complete a PhD before retiring. Every Saturday, he came to the library to work on his research, something related to nineteenth-century Tamil theatre.

As I scanned through the recipes from the newspaper, mostly cakes and jellies for New Year's Eve, he glanced at my screen and said, "My grandmother had a notebook with a new...