As our lives become ever more connected, there are so few places we can go to truly be alone anymore.

Take airplanes. Airplanes were once disconnected sanctuaries where you had nothing to do except read, daydream, or doze off—“a retreat in the sky,” in the words of one Buddhist monk. But that’s no longer the case. On a flight recently, a teenager across the aisle from me wasn’t just watching a movie, but watching a movie on one screen and playing games on another—while a nearby passenger was working on his laptop, checking Facebook on his smartphone, and watching a show on the small television in front of his seat. We may be “alone.” But we’re not really alone.

There’s been a lot of attention devoted to how technology is scattering our attention and corroding our relationships, but less to how it’s impairing our capacity for solitude. We’re so overstimulated that being alone has become unbearable—a fact that was highlighted in a series of studies from 2014, where people preferred giving themselves electric shocks rather than sitting still alone in a room for  6 to 15 minutes. In the lab, we shock ourselves; in real life, we reach for our phones in a lecture hall, in line—even when we’re driving.  

But to live a good life—and to become mature individuals—we need to be content with being alone with our own thoughts. That’s because the only way we can come to understand who we are and think through the critical decisions about our lives is through the self-examination that occurs in solitude.

That idea lies at the heart of a thoughtful new book Lead Yourself First by Sixth Circuit federal judge Raymond M. Kethledge and the CEO of the Character & Leadership Center Michael S. Erwin. The book tells the stories of many inspiring leaders throughout history who relied on solitude at crucial moments in their lives, from Winston Churchill and Pope John Paul II to Martin Luther King Jr. and Aung San Suu Kyi.

Through meditation, prayer, and writing, these leaders refined their thoughts, found inspiration, and developed moral courage. Dwight D. Eisenhower, for example, wrote memos to himself to clarify his thinking in the lead up to D-Day, while Jane Goodall discovered the social habits of chimpanzees—and their remarkable likeness to humans—by exploring Tanzania’s Gombe Stream National Park alone. And many of the most crucial discoveries and innovations in science and art were forged in the crucible of solitude. Marie Curie stumbled upon the dynamics of radiation in the isolation of her lab and T. S. Eliot conceived of his masterpiece “The Wasteland” while on sick leave at a hospital. Only when the mind is at rest can we actually hear ourselves think.

But as the authors point out, you don’t have to lead armies, corporations, or artistic movements to benefit from solitude. Kethledge and Erwin tell the story of a Texas mom named Dena Braeger who relies on solitude to raise her children.

One day, one of Dena’s daughters was being mean to her sister.. “I was super irritated,” Dena said, “and I disciplined her in the moment.” But Dena’s response didn’t end there. She spent two days thinking about the incident and realized that what really bothered her was her daughter’s “quickness to take offense.” She wanted to inspire her daughter to overcome this weakness, and her solitary reflections led her to this insight: Rather than telling her daughter what she was doing wrong, she would talk to her about her strengths, and then gently point out where she could improve. She told her daughter “that people will disappoint you at times you expect and don’t expect, and that a more peaceful way to go through life is not to be constantly offended by these things.” For Dena, solitude led to a creative and thoughtful form of discipline.

Of course, creativity is one of the many benefits of solitude. But the benefits of solitude don’t end there. One study by the psychologist Reed Larson showed that adolescents who spend time alone are less likely to be depressed, do better in school, and feel less self-conscious when they’re by themselves.

Paradoxically, it also strengthens our relationships. In studies of children at a device-free summer camps, the kids became more empathetic after spending time unplugged. “You have nothing to do,” one boy said, “but think quietly and talk to your friends.” Sherry Turkle, the social scientist who has conducted some of this research, says that “we find ourselves” in solitude: “We prepare ourselves to come to conversation with something to say that is authentic, ours. If we can’t gather ourselves, we can’t recognize other people for who they are. If we are not content to be alone, we turn others into the people we need them to be. If we don’t know how to be alone, we’ll only know how to be lonely.”

Though solitude brings many benefits with it, it’s quickly being crowded out of our lives. Our minds are constantly assaulted by a sea of inputs—texts, emails, ads, and notifications. According to psychologist Adam Alter, author of the book Irresistible, people spend nearly all of their free time—those precious three to four hours of each day—in the company of a screen. Which means they spend virtually no time alone.

But there are ways to make space for solitude in our lives. In his book, Alter suggests this simple tip: put your phone far away from you when you’re working or trying to be alone. That simple barrier will make you less likely to check it frequently. He also mentions the example of a German company that automatically deletes employees’ incoming emails when they’re on vacation. That way, if they want to unplug, they really can. If your company doesn’t have a policy like that—and it probably doesn’t—you can engineer something like it in your own life by, for example, deleting the email app on your phone when you’re on vacation.

Kethledge and Erwin also offer advice. If you want to reclaim solitude, they suggest you should take advantage of the moments of solitude already programmed into your life. You don’t need to go into the wilderness for 40 days to be alone—you just need to turn the music off when you’re driving to work or preparing dinner, or leave your phone in your pocket when you’re waiting in line or for an appointment.

It requires discipline, but a discipline that brings with it many rewards. The pediatrician and psychoanalyst Donald Winnicott once said the capacity for solitude is “one of the most important signs of maturity in emotional development.” Though it can be hard to resist the siren call of technology and sit still with your own thoughts, part of being a fully developed human being is making that difficult choice. When there’s no solitude, there’s no self-examination—and without self-examination we can’t grow and become better for ourselves and for those around us.

Emily Esfahani Smith is the author of The Power of Meaning: Crafting a Life that Matters. Follow her on Twitter @EmEsfahaniSmith and find her at Facebook here. Emily is an instructor in positive psychology at the University of Pennsylvania, as well as an editor at the Stanford University’s Hoover Institution, where she manages the Ben Franklin Circles project, a collaboration with the 92nd Street Y and Citizen University to build meaning in local communities.