On a quiet Sunday evening, Bert and Edna, married 55 years, rocked on their porch swing with lukewarm tea. “Let’s talk bucket lists,” Edna said. “Mine’s simple—remember where I put my pants,” Bert joked. Then, after some thought: “Skydiving.” Edna scoffed. “You faint tying your shoes.” She chose her own “goal”: confessing mischief. She admitted sabotaging his recliner with a...