Over the past decade with AT&T, John Donovan has served as CTO, CSO and group president for technology and operations—and most recently, CEO AT&T Communications. He credits his success to two factors: “amazing parents and a hometown that keeps me honest.”

What is something you’ve learned that you lean on daily?

The answer to that question has changed over the course of my life, but right now, I think something I lean on every day is the way I grew up. I’m from a large family, and I was raised in a small house in an inner-city, working-class neighborhood. That helps keep me grounded and grateful, and the older I get, the more I lean on those early lessons.

Life is much easier when you’re true to your genuine self, and when you’re in a very large-scale job like CEO, you have to know your principles and values. Decisions need to come instinctively, from the core of who you are.

As you gain power in your career, the call home becomes increasingly important. You don’t need a “network.” What you need are advocates and friends—people who will push you, tell you what you don’t want to hear and remind you where you came from. My mother, for example, has an incredible ability to simplify things. She’ll tell me, “I don’t know how you keep all that stuff organized in your head, but I hope you’re finding time to be nice to someone every day.”

What one piece of advice would you give someone starting a company?

Get the people right. Your business plan, your competitors, your opportunities and threats—all of that will change over time. What will make you successful is people, and relationships small and large. Small in that you need a good team around you and you all need to be on the same page, and large in that you need to understand your customers and employees at the collective level.

Entrepreneurs often overlook people and culture problems early on. They see them as growing pains. But if your engineering team is fighting with your sales team, they’re more likely to grow into that behavior than to grow out of it, and that will inhibit success. When a small company hits a ceiling, it’s rarely about revenue or locations or head count. It’s about culture.

What small change has made a big difference in your life?

Writing long-term plans. They help me do a couple of things. One, hold myself accountable. If I’ve written down that I want to see the best in others over the next ten years, I might realize when I revisit my plan that I’ve been making snap judgments and need to focus more on that area. The other benefit of a long-term plan is that it helps me stay above the fray. I’m less likely to get caught up in the storm of today or tomorrow, and I can survive painful situations because I have longer-term objectives in mind.

I wrote my first long-term plan when I was 26. It covered the next three decades—until 55, when I thought I was going to retire. But because I was young and immature, that plan was all about what I wanted to do as a businessman. It didn’t say anything about being a husband or a father. A couple of years ago, I wrote a new plan, for the rest of my life. This one covers every dimension—not just professional, but personal, familial, spiritual. I’ve reread it every six months or so since, and so far, I haven’t felt the need to change it.

What don't you know that you wish you knew?

The first thing that comes to mind is something I know now, but wish I’d known much sooner. I’m really happy with how I’m managing my time and the stress of this big, complex job. If I’d had that ability 30 years ago, I think I could have been a lot more productive.

I used to be completely controlled by what I call “the monkey,” which is the part of your brain that’s always worrying about the past and the future. If you have a meeting tomorrow morning about the reasons for suboptimal financial results last month, the monkey might spend a lot of time beforehand thinking about it and wondering what went wrong. But all that time is wasted. You can worry about it during dinner with your wife, or during meditation in the morning, but either way, the meeting isn’t happening until 8 a.m.

Several years ago, I killed my monkey. I actually named him and hunted him down. It’s not that I don’t worry now. It’s that I plan my worry time. I don’t allow myself to be preoccupied with the meeting before it happens, and that makes room for some very important stuff. For example, I pick a virtue every month now—something I want to focus on improving. This month is diligence; February was humility. I’ll start the day reminding myself to focus on that, and at the end of the day I’ll take a little time to assess and hold myself accountable. I don’t think I’d have time for that if the monkey were still in charge.

What books are on your nightstand right now?

I’m usually reading three books at once, because I want something that’s entertaining, something that requires light concentration and something that requires deep concentration. Right now, I’m in the middle of Perfect Weapon, by David Sanger of The New York Times, which is about the hack of the DNC. I’m also reading Gang Leader for a Day, by Sudhir Venkatesh, which is about the drug trade and violence on the south side of Chicago, and Just Mercy, which is a memoir by Bryan Stevenson, who became a lawyer to fight racial bias in the criminal justice system. I tell my kids to see reading as a conversation with the author—and to research the author before they start a book, to make sure they’re someone worth spending time with.

I’m often reading multiple books on similar topics because I get obsessed with fully understanding a subject. A couple of years ago, I read probably a half-dozen books on quantum physics and quantum energy, and then I met with a professor at CalTech. Before I read Gang Leader for a Day and Just Mercy, I read Frederick Douglass’s autobiography, watched Selma and 13th, read a bunch of papers, and met with Ava DuVernay, Al Sharpton and Oprah. The goal isn’t simply to learn, but to do something with that information. At AT&T, we just launched a program called “Believe Chicago” that works to help improve lives in theand lift 19 Chicago neighborhoods most affected by gun violence and high unemployment. It’s up to our company to be a good, compassionate neighbor, doing all we can to promote jobs, education and safety. We plan to take what we learn from Chicago and apply it in other cities.

When did you realize you were wrong about something?

Remember when the iPhone first launched in 2007? It was exclusive on AT&T—and our network was tested. I was CTO at the time, so I was responsible, and it felt like living through nuclear winter. It was like that movie The Martian, but worse, because I was isolated and at the same time had people all around me who were looking at me like they wanted to kill me! Like The Martian and The Walking Dead combined, maybe.

Realizing I was wrong was easy. The self-assessment is more important. You have to resist the urge to rationalize your mistakes. I think you’d be hard-pressed to find a great executive in a great company who isn’t humble enough to realize they make mistakes every day. I often hand out cards to someone starting a new job with phrases to learn—like, “I don’t know,” “I made a mistake,” “I’m sorry” and “Help me out.” We have to get comfortable being wrong, because that’s how we get better.

We also have to get comfortable forgiving ourselves for our mistakes. A few years ago, I created probably the best document I’ve ever written. I wrote down every mistake I could remember making, I reread it a couple of times, and then I erased it. It was my way of pulling out all that hidden baggage so I could move forward without it.

What unit of time matters the most and why?

The first three hours of the morning. I get up at about 4:15 a.m., and I literally do not touch an electronic device until about 7:15 a.m. That may sound crazy, but I’ve found I can move through the day much more quickly when I own those three hours. I meditate, I ride a bike, I read, I go to church, I plan and strategize. I don’t think it matters what the routine is, just that you have one and that it gives you space to think about the big picture. If I successfully protect that time and use it wisely, I’ll be far more productive as the day goes on.

Hard-won advice