Greatest Secret in the World: The Powerful Book that Unlocks a World of Personal Happiness and Achievement By Og Mandino

Og Mandino develops the lessons of The Greatest Salesman in the World into a practical program of reflection and habit-building. Checklists, questions and guided prompts help readers consider how values from the earlier fable might be applied in daily life.

The focus includes persistence, emotional habits and one's understanding of achievement. This is motivational self-help rather than military strategy, and its language of success is not a guarantee of income, happiness or a particular result.