I’ve learned to filter problems before I decide how much to care about them. We all have an endless supply of issues to deal with, so it’s helpful to think carefully about whether each one is really material. I’ll ask myself if an issue is something I’ll even be thinking about six months from now, how much it matters, and most important, whether it’s truly a problem in the first place. So many of the things we worry about never actually happen. You look back at the end of the day and realize out of 100 concerns you had, most if not all of them didn’t have an impact. When you examine and challenge those so-called problems up front, you can save a lot of time and energy.

You need a way to sharpen your thinking. Most often, it’s a person or group of people you can talk to. It doesn’t have to be a co-founder—it can be a mentor, or a spouse or your leadership team—but wherever you find it, that dynamic feedback is critical. It takes a level of vulnerability that a lot of new CEOs don’t have, because they feel like they can’t admit when they don’t know what to do or they may have made a mistake. But for me, thought partnership is really important.

At AdMob, I had different thought partners over time. Certainly, Jim Goetz, who was on the board from Sequoia, made a huge difference and was an important mentor to me, as was the rest of the board. I remember at one point, we had a lot of friction between Sales and Engineering because the engineers were all busy with long-term projects, and whenever a customer needed something short-term, it would throw everything off. They weren’t big tasks—they might take a day or two—but it was hard to constantly context-switch. One of our board members, Maynard Webb, explained that when he was COO of eBay, they’d assigned a set percentage of the engineering staff to handle just those short-term projects. He said you can’t know what those projects will be, but you do know they’ll exist. We did the same thing, and it made everyone happier and more productive. There are so many things like that to process and ponder and improve, and you need those ongoing, interactive conversations.

Investing in personal friendships. That gets harder as we age, I think, because our social relationships are increasingly defined by work and family. About 10 years ago, I looked around and realized almost all of my friends were either colleagues or the parents of my kids’ friends, and I decided to focus more on my relationships outside of those contexts. We moved to Southern California specifically so we could be closer to our family and friends, and I started spending more time with a group I knew from college. We all live within a few miles of each other now, and we’re really close—we take trips together, and go biking or play board games every week.

I think it would be cool to know a bunch of languages. I speak English and Arabic and a little bit of Spanish, but I’d like to learn more. What I’m most interested in isn’t necessarily the languages themselves, but what they do to your brain. It’s like any kind of education—the most valuable part is learning how to learn. I don’t remember a lot of specifics from studying computer science, for example, but it certainly changed the way I think. Figuring out the logical, step-by-step path a computer takes to solve a problem helps you analyze your own problem-solving approach. I’m sure the same would be true for learning music, or psychology, or a language I don’t speak. That simple process of adapting to a new way of thinking gives you abilities you didn’t have before.

I usually read one at a time. Right now it’s a sci-fi book called The Ghost Brigades, which is the second in John Scalzi’s Old Man’s War series. The premise is basically that humanity is at war with a bunch of alien civilizations, and anyone 75 years old or older can volunteer for 10 years of military service in exchange for a new, 20-year-old body.

Most of the books I read aren’t very serious. The ones that take 300 pages to tell you one thing generally bore me; I don’t really like directed lessons. I read a lot of fiction, and about half is fantasy and sci-fi. One of my favorites is The Unincorporated Man, by Dani Kollin and Eytan Kollin, which is about a man who froze himself and woke up 300 years later to find that civilization had collapsed, but the corporations all persisted. Every individual person was incorporated—rather than take out a loan for college, you would sell shares of yourself and then the corporation would control you until you earned enough to buy your freedom. I thought it was fascinating. Fiction is often so much more expansive than nonfiction, and I like thinking about how those imaginary scenarios apply to the world we live in today.

I have lots of examples of being wrong, but I think of it more in terms of wishing I could have tried out both choices. I’d love to know what was behind all the doors I didn’t walk through. In general, I’m extremely comfortable—probably frustratingly comfortable—with changing my mind. I might be adamant about something one day, and then get new information and say the opposite thing the next week. If it’s one of those rare irreversible, bet-the-company decisions, you do need to sit down and think very carefully about whether it’s worth the risk. But if it’s just a bet-the-quarter or bet-the-week decision, you can recover.

Very few decisions are truly irreversible. At AdMob, betting on the iPhone was one. It came out after we launched, and we essentially adjusted all new product development to this new, unproven platform. That ended up being the right call, but if we’d been wrong, it would have been a big mess. Selling AdMob was another bet-the-company moment. A lot of good came out of that decision, too, and I wouldn’t say that it was wrong, but I’d still be curious to see what would have happened if we hadn’t sold.

One that comes to mind is the first hour of the morning. My wife and I have coffee, talk about the plan for the day and then wake up the kids and get them off to school. I definitely feel the absence of that time when I’m traveling, and I miss it.

More broadly, I think a year is meaningful, both because it’s enough time to do something significant and because we tend to take a natural pause when it ends, where you can reflect on the previous year and plan for the next one. Looking backward and forward over that time frame allows you to isolate the important stuff. You can ask yourself, “Did I do what I wanted to? Did I use my time well? What did I learn, and how I am going to apply that?” New Year’s resolutions are a nice summary, but I think it’s useful to go more in-depth and think about everything you want to accomplish.