His conference there was concluding when he realized that he’d mistakenly booked his flight home for a day later, meaning that he was stuck in Ottawa, a city where he knew no one. Standing in his high-floor hotel room after all his colleagues had left and looking through the window at the busy street below, he had an unexpected insight. “I suddenly had a perfect sense of how loneliness feels. I could see the world around me, but I was not part of it.”