I was eight, and through my bedroom wall I could hear my mother, Heidi, talking to herself as she prepared to go to sleep. Every night, in the living room, she positioned old magazines beneath the legs of a red convertible sofa, so as not to crease the rug it rested on. Then, with audible effort, she lifted the bed out of the couch, arranged layers of sheets, blankets, and quilts, and at last put ...