By being all things to all people, a project manager can run the risk of being nothing to oneself. They have the thankless task and role of delivering value whilst managing constraints. You can only go as far as your knowledge base takes you, and if you don't know more you cant do more, project manager or not. The book propounds that, above the tools and techniques available to a project manager, it is the people that deliver value and are the difference between the ability or inability to realise project benefits. Therefore, "make me MVP" - I am the Most Valuable Player.