Enjoy this excerpt from our new book, Healthy Leadership.

When Sara was a student, she was a terrible test-taker and had a very hard time retaining what she read. At 16 years old, her parents separated, and she lost a close friend who was run over by a car while they were riding bikes together. This trauma, coupled with Sara’s learning struggles, created intense emotional and academic obstacles during high school.

At one point, Sara’s dad handed Sara a set of cassette tapes by Dr. Wayne Dyer called How to Be a No-Limit Person. Dyer talked about things like the power of positivity, the ability to visualize and manifest what you want in life, how to embrace failure, and how to train your brain to respond to life’s challenges in a way that propels you forward instead of holding you back. In short, mindset.

Upon entering the world as an adult, Sara knew what she wanted to do with her life: become an attorney like her father. So, she did what all aspiring lawyers must do after college: take the LSAT. Unfortunately, she did very poorly on her first attempt. Yet she was undeterred.

Her father had raised her to see failure as an opportunity to learn from past mistakes and do better in the future, which is what she planned to do. She signed up for a prep class, studied even harder, took the test, and did even worse the second time.

Sara stepped away from her dream of becoming a lawyer. Even so, she didn’t stop dreaming about a great career, though her life certainly wasn’t turning out to be the success story she had imagined. After a short-lived job as a chipmunk at Disney World, she got a job selling fax machines.

Going door-to-door, trying to convince strangers to listen to her sales pitch, was no walk in the park. Doors were slammed in her face, sometimes she broke down in tears, and a few times the police were even called on her.

But still, she didn’t give up. She understood that she could benefit from these seemingly negative experiences. She knew she could control how she thought about the challenges she faced.

As she later remembered, “During my fax-selling stint, I would spend much of my free time trying to figure out what I really wanted out of life and what my strengths were. I knew I was good at selling and that I eventually wanted to be self-employed. I thought, instead of fax machines, I’d love to sell something that I create and actually care about.”

And that’s just what she did. After seven years selling fax machines, Sara realized that women needed a better kind of “shapewear” than old-fashioned stockings. So, she founded her own company, Spanx, and used the sales skills she’d honed going door to door to sell her products.

This is how Sara Blakely became the self-made billionaire she is today. And she credits this incredible success in large part to what her father taught her about the power of positivity.

As Blakely puts it, “I’m now the founder and CEO of Spanx, a company I built from scratch with $5,000 in savings. It wasn’t because I aced all my classes in school—it was because I studied the art of mindset.”

Positivity changes us for the better, and it builds psychological strengths. Research shows that people who experience more positivity become more optimistic, open, and driven by a sense of purpose.

Positivity further helps to build good mental habits and spurs people to find multiple pathways toward a goal or through a problem. Even an individual’s resilience is improved with positivity because people can bounce back from challenges more quickly.

Positivity also helps people create and strengthen social connections. It leads you to build more and better relationships.

Finally, positivity improves physical health by reducing stress hormones and increasing brain chemicals that result in decreased inflammation and improved immune functioning. Positivity is medicine for our minds, bodies, and lives.

Healthy Leadership Book