Most people "believe the only way to earn more money is to work more hours," Siebold writes. Meanwhile, "the rich know that creative thinking is the highest paid skill in the world."
High earners believe money flows from ideas and finding solutions to universal problems, he says: "The bigger the solution, the bigger the paycheck. … Making money may not be easy, but it is simple."
Siebold isn't the only one who believes getting rich starts with your mindset. It's a concept that journalist Napoleon Hill preached in his 1937 personal finance classic "Think and Grow Rich," the culmination of his research on 500 self-made millionaires.
"Riches begin in the form of thought!" Hill wrote. "The amount is limited only by the person in whose mind the thought is put into motion. Faith removes limitations!"
At the end of the day, "the secret has always been the same: thinking," Siebold emphasizes.