“When you reach the age of 100, suddenly, even if you did nothing notable, you are a celebrity,” writes Morrie Markoff, who passed that milestone a whopping six years ago. “When perfect strangers find out, they shake your hand, as if, by osmosis, you can transfer the secrets of long life to them.” Markoff, an artist specializing in metal sculpture and the author of Keep Breathing, which he wrote at 103, spills his wisdom in the form of handwritten essays he uploads to a blog about once a month. Titles range from “Choose your mate wisely” (Markoff recently lost his wife, who was 104) to “Pandemic—1918 to 2020” (he was four during the Spanish Influenza, which claimed the life of his older brother) to “Another day,” in which he writes, “I opened one eye to look at my bedside clock. I closed my eye. I still had 15 minutes to go before I knew Danny would be shaking my shoulder rousing me out of bed. If you saw Danny you too would offer no resistance. I got out of bed.” —J.V.