I've read many good investment books but this one is important as it offers unique and highly valuable insights. Unlike most other investment books it focuses on the behavioural aspects of investing not on stock selection.
It examines and explains both the bad and good traits that will cause an investor to either be successful or a failure. These insights have been gained by a detailed analysis of a large group of established highly experienced investors. This approach has revealed and characterizes winning investments styles that I've not seen described before, specifically the 'Hunter' and the 'Connoisseur'.
As an investor of twenty years - and still feeling like a novice - this book will I think be the most important in influencing my style of investment. Successful investment is an internal battle with ones' own psychology - this book tells you how to win that battle.
I recommend it highly.