When my husband looks shyly proud of his software architecture, I remember G.H. Hardy and this little book. There is an almost Japanese beauty and sadness about his far reaching if imperfect mind and a spirit that is easy to care about and understand.
Pros: A wonderful read about what mathematicians think about when they are too old to think about numbers anymore. Cons: Sad to think about being among the best in the world at something and then being too old to do what you love.
Inspiring book if you feel like doing great things, especially in science or maths. Very unapologetic though, Hardy shunned mediocrity and mental weakness, even though in a stylish and British way, so it's a pleasure to read anyways.