In Think and Grow Rich, Napoleon Hill illustrates a secret concerning accumulating wealth that was brought to his attention by Andrew Carnegie, a man who built an industrial empire which made him the 4th richest human being of all time (an inflation-adjusted net worth of 310 billion USD).
Everything begins with a thought. Whether you are deciding what to eat, your career path, or even what you generally want out of life, the first thing that occurs is a thought. One of the greatest assets we can ever acquire is to know that an intangible impulse of thought can be transmuted into its physical counterpart by the application of known principles.
All it takes is one idea to become a success. And when riches do begin to come, they arrive so quickly and in such large amounts that you will wonder where they have been hiding throughout your life.