I think this is well written but slightly dragged out. The author becomes curious about people with amazing memories and follows them to competitions and then learns how to do it. The techniques are interesting and they work if we are willing to put in the massive amount of work required to really excel. But even if we don't want to work that hard, we will pick up some useful tricks.
The author makes the point at the end, that as good as these techniques are, they don't improve our everyday memory - like where we put our keys, etc., but they do give us ways to memorise long lists of things from numbers to poetry, etc., if we want to do that.
