It’s Girl Scout cookie season, which means that soon I’ll be enjoying one of my favorite cookies—Do-si-dos. (In case you’re wondering, those are the ones with oatmeal on the outside and peanut butter on the inside.) The sale of millions of Girl Scout cookies brings to mind the remarkable Frances Hesselbein, CEO of the Girl Scouts of the USA from 1976 to 1990. It was Hesselbein who rescued Girl Scouts from near-irrelevance and transformed it into a modern organization dedicated to empowering young women. Under her guidance, the organization grew to serve 2.25 million girls.

Hesselbein reportedly doesn’t like to talk about her age, but according to Google she’ll be celebrating her 100th birthday in November. Still working, she’s a living legend in the field of leadership development. Early on, she teamed up with Peter Drucker to reinvigorate the Girl Scouts by making the organization more professional and increasing its focus on leadership, science, technology and math.

She turned the Girl Scouts into a world-class organization, tripled the number of minority girls it served (at a time when Girl Scouts were predominantly white and middle class), developed a contemporary curriculum and gave girls hands-on experience in addressing the challenges in their communities.

After she left the Girl Scouts, she became the founding president of the Peter F. Drucker Foundation for Nonprofit Management, a group dedicated to fostering innovation and excellence among nonprofits. It was renamed the Leader to Leader Institute after Drucker’s death in 2005 and became the Frances Hesselbein Leadership Institute in 2012. Hesselbein still serves as the institute’s president.

You can learn more about Hesselbein and her work on the institute’s website. I recommend her “Moments of Insight” interviews, three short videos that won’t take you long to watch.

Here are some of pearls of wisdom from Hesselbein on leadership:

“Leadership is a matter of how to be, not how to do.”

“The character and quality of the leader determines the results.”

“We never compromise our principles—who we are—because once we’ve done that, we cannot go back to the level we have struggled to maintain.”

“All of us have a defining moment, whether we are conscious of it or not, that determines the person we are—the leader we are today.”

“Leadership is a journey, not a destination.”

“As long as we are breathing, we can be leading.”

And here, reduced to three key points, is the essence of Hesselbein’s formula for leadership:

Be mission-focused

• Begin with a short, powerful, compelling mission statement that is based solely on…
  • Why do we do what we do?
  • What is our reason for being?
• Distill the language until you have a powerful mission statement. (“Peter Drucker says it has to fit on a t-shirt.”)

Be values-based

• Define the values and bring them to life so they are more than a plaque on the wall.
• Talk about the values often, and live them.
• Your people will watch you.
• If you’re living your values, everyone else will try to live them, too.

Be demographics-driven

• Reach out and bring into the organization remarkable leaders at every level from every racial and ethnic group.
• Ask yourself this question: “When the people we want to bring into our organization look at us, can they find themselves?” If the answer is a resounding “yes,” you’re the organization of the future. If the answer is “We’re not very diverse, but that’s what we’re going to do in the future,” then, sorry, you’re already part of the past.

We can learn a lot from Hesselbein. At 99, she possesses more passion and purpose than most people half her age!