When my mother was diagnosed with diabetes in her early 70s, long before her memory started to deteriorate, she immediately went out and bought two AccuCheck machines in case one broke. She kept them side by side on the dining room table, next to a squadron of test strip vials. The thought of being unable to monitor her blood sugar terrified her for much the same reason being without a scale terrifies the person with an untreated eating disorder. As a home health social worker I’d evaluated hundreds of patients my mother’s age....