Neurologist/author extraordinaire David Eagleman, discussing his brand new book Livewired: The Inside Story of the Ever-Changing Brain at one of yesterday’s Edinburgh International Book Festival sessions, makes a point many of my acquaintances are well aware of, at least in the superficial way of having read about it in a newspaper: “People who cognitively challenge themselves their whole lives end up much better off than people who just retire and their lives just shrink.” Good to know but that “challenging” attribute is more itch than strategy. In my experience, either you’re driven (almost to an unhealthy extent) to keep pushing your mind or you’re unaware of how much work is required, unaware that a Sodoku a day makes little difference.