Easy and familiar decisions, ones that we understand and are comfortable with, are never a problem. Decisions beyond what we know, or in which we are not confident or are simply scared about, can cause us anxiety and rightful concern.
If you can just phone a friend or relative who is a mentor to you and offers wise advice to help you through life's larger challenges and uncertainties, then you do not need to listen to this book.
If, on the other hand, like the author, life has not provided you with mentors of any kind, it can be very lonely making challenging decisions. If your friend's or relative's usual advice is such that you would rather risk failure than ask their advice (because their advice is usually rubbish) then you probably need to make your own learning about what makes for a good decision, what does not and all the curly bits in between.
This book is simple, short and to the point. It references the life experience of the author and people he has known. It offers a repeatable model for maturing your decision-making skills.
It is for the benefit of those in the world who, like the author, have little or no wisdom available to them but nonetheless want to make their way in this ever changing, and challenging world, with confidence.