Jim Rohn made the biggest impact on personal development in business and life. He's been called the Godfather of Personal Development, he's been implementing new different ideas and methods of personal and spiritual growth, into the ruthless business world of 60s', 70s', and 80s'. The concepts that Jim taught in his seminars, courses, and books are widely used in today's business as the gold standard by more and more successful individuals, businesses, and organizations.