It took a couple of large setbacks for John Chambers to realize that he could overcome anything.

"We’re a product of the challenges we faced in life," Chambers, the CEO of Cisco Systems, Inc. said. "And how we handled those challenges probably had more to do with what we accomplish in life."

Chambers has dyslexia, and he struggled in school—at the time, dyslexia was not a known disability.

One of his teachers in grade school helped him face his dyslexia and persevere through his disability.

From pushing himself through an early challenge, Chambers went on to successfully complete law school at West Virginia University. He also earned a business degree from Indiana University.

Once Chambers took over as CEO of Cisco in 1995, he quickly made improvements, increasing the company’s revenue by billions of dollars.

However, in 2001, Cisco fell into a financial crisis. Chambers, remembering his struggle—but eventual success—with dyslexia, used his leadership and perseverance to pull his company out of the crisis.

Even though Chambers continues to struggle with dyslexia, his no-fail attitude has helped him keep Cisco one of the most powerful companies in the world.

You can read more about Chambers' story on the New York Times website and on The Power of Dyslexia website.