No one expects Magic Johnson to offer proof of the Riemann hypothesis anytime soon, yet his wealth is estimated to be half a billion dollars. In Johnson's case, he developed non-academic skills that he could use to obtain a high salary. By saving that salary and investing, Johnson earned far more money through passive income than by active means.

Contrast that with Chris Langan. His story is a classic example of how little correlation there can be between intelligence and financial reward. Raised in poverty by a single mother, Langan dropped out of two colleges and has worked a series of manual labour jobs ever since. This is despite being billed as "the smartest man in America," and having an IQ measured at 195. In between his shifts as a bouncer, Langan single-handedly devised a theory that unifies science and theology. That theory might have vast promise for human understanding, but it doesn't pay Langan's bills as efficiently as his current job as a horse rancher.

Applying Your Knowledge

Every market has an opportunity waiting to be exploited, and that exploitation doesn't necessarily require vast intelligence. Harvey House founder Fred Harvey never attempted to formulate a scientific theory, but he did notice that people disembarking at train stations often wanted something to eat and a place to spend the night. Armed with that knowledge, he became one of the hospitality industry's most successful entrepreneurs.