This is the 101st instalment in a series on dementia, including the research into its causes and treatment, advice for carers, and stories of hope. My mother and I often walked together during the time I cared for her, around the garden or in the fields beyond it. Sometimes she resisted, complaining she was too tired or inventing some small ailment as an excuse not to get up and get out (“My legs are sore”). But once outside she always responded, and she always returned to the house in a better...