By Lawrence Reed, President of FEE.org

This is an excerpt from his book, Real Heroes: Inspiring true stories of Courage, Character, and Conviction.

In the 2007 book Thanks! How Practicing Gratitude Can Make You Happier, Dr. Robert A. Emmons reveals groundbreaking research into the emotion we call gratitude. As Emmons defines the term, gratitude is the acknowledgment of goodness in one’s life and the recognition that the source of this goodness lies at least partially outside oneself. I think this was the secret to Anne Frank’s character.

Years of study by Emmons and his associates show that “grateful people experience higher levels of positive emotions such as joy, enthusiasm, love, happiness, and optimism, and that the practice of gratitude as a discipline protects a person from the destructive impulses of envy, resentment, greed, and bitterness.”

A grateful attitude enriches life. Emmons believes it elevates, energizes, inspires, and transforms. The science supports him: research shows that gratitude is indispensable to happiness (the more of it you can muster, the happier you’ll be) and that happiness adds as many as nine years to life expectancy.

Gratitude is much more than a warm and fuzzy sentiment. And it does not come automatically, unthinkingly. Some people feel and express it all too rarely. And as grateful a person as you may think you are, chances are you can develop an even more grateful attitude. Doing so carries ample rewards that more than compensate for the task’s moral and intellectual challenges. If Anne Frank could do it with all that was going on around her closeted world for two years, you and I have few excuses for failing to muster gratitude as well.

The English writer and philosopher G. K. Chesterton once said, “I would maintain that thanks are the highest form of thought; and that gratitude is happiness doubled by wonder.”

Think about that, especially Chesterton’s use of the word wonder. It means “awe” or “amazement.” The least-thankful people tend to be those who are rarely awed or amazed.

A shortage of wonder is a source of considerable error and unhappiness in the world. What should astonish us all, some take for granted or even expect as an entitlement.

We enjoy an endless stream of labor-saving, life-enriching inventions. We’re surrounded by abundance in markets for everything from food to shoes to books. We travel in hours distances that required weeks or months of discomfort for our recent ancestors.

In America, life expectancy at age sixty is up by about eight years since 1900, while life expectancy at birth has increased by an incredible thirty years. The top three causes of death in 1900 were pneumonia, tuberculosis, and gastrointestinal infections. Today we live healthier lives and live long enough to die mainly from illnesses (such as heart disease and cancer) that are degenerative, aging-related problems.

Technology, communications, and transportation have all progressed so much in the past century that hardly a library in the world could document the stunning accomplishments. I still marvel every day that I can call a friend in China from my car or find the nearest coffee shop by using an app on my phone. I’m in awe every time I take a coast-to-coast flight, while the guy next to me complains that the flight attendant doesn’t have any ketchup for his omelet.

None of these things that should inspire wonderment were inevitable, automatic, or guaranteed. Some see it all and are amazed and grateful. Others see it and are jaded and unappreciative. Which are you?

A message of hope. Anne Frank’s message will be remembered for many decades to come—forever, I hope. It reminds us that, no matter the circumstances, we can brighten our lives and those of others. We don’t have to sink into despair. We can find good in the smallest of things even as we confront the biggest of evils. Our attitude, the old saying goes, determines our altitude. If you want to make a better world, start by making a better self; it’s the one thing you have considerable control over in almost any situation.

Anne Frank didn’t live long enough to see or possess very much. But because she found within herself an undying gratitude for what she had—and an awesome ability to communicate it—we can be thankful that she inspires millions to this day. No matter how old you are, you can learn some critical life lessons from this brave teenage heroine.