IN FEBRUARY 2024, the New York Times crossword editor Will Shortz was sitting at his desk in Pleasantville, hard at work around 11 p.m., when he shifted to the left and found he couldn’t shift back. The side of his mouth was drooling. Shortz recognized the signs: He was having a stroke. Later, at the hospital, he had a second, larger stroke and then, after thrombolysis to dissolve the clot that caused it, a brain bleed—a rare and serious complication. He spent ten days in intensive care, prognosis uncertain, before he was stable enough to move to an inpatient rehab center, where he would begin the long work of recovery. Early on, Shortz said, the doctors offered him a sliver of good news: The strokes had affected the right hemisphere…