The Surprising Reason Why This Young Tech Entrepreneur Swears By Pen and Paper Codecademy founder Zach Sims says his top productivity strategy is all about unplugging.

Editor's Note: Entrepreneur's "20 Questions" series features both established and up-and-coming entrepreneurs and asks them a number of questions about what makes them tick, their everyday success strategies and advice for aspiring founders.

The most effective entrepreneurs know the secret to continued success is to never stop learning. Zach Sims gets this. As the founder of Codecademy, an education company that teaches users technical skills, including how to code, Sims is looking to help people take their career to the next level.

Sims founded Codecademy when he was just 20 years old and an undergrad at Columbia University in New York City. In 2011, he left school to pursue the business full time.

The decision paid off. Today, Codecademy serves more than 45 million learners around the world and the company has raised $43 million from investors like Richard Branson. In addition to the free and paid courses that are available, Codecademy also counts big names like IBM, Microsoft, Google and Salesforce as enterprise customers.

We caught up with Sims to ask him 20 questions and find out what makes him tick.

This article was edited for brevity and clarity.

1. How do you start your day?
I usually try to wake up around the same time every morning. I'll make tea, meditate for a bit and write out priorities for the day and then usually I exercise. I find having that hour and a half in the morning where I'm not working really helps make it easier to stay focused the rest of the day and get started in the right headspace.

2. How do you end your day?
Most of the time I'll end up reading for a little bit, usually 15 minutes at the end of the day. My Kindle is next to my bed, and I'll read before I go to sleep, as it helps to shut my brain down.

3. What's a book that changed your mind and why?
Why We Sleep by Matthew Walker. I think for a long time I had thought that I could get by sleeping six hours a night and everything would be fine. But in the book, it explains how it's not just about if you can survive on a little bit of sleep but also what happens to your body over the long term when you deprive it of sleep. I used to think of sleep as the first thing that could be sacrificed, now I think of sleep as something that I can't not do.

4. What's a book you always recommend and why?
Andy Grove's book High Output Management. I think it's a tactical, hands-on guide for what you need to do to be an excellent manager and work in a growing business.

One of the most interesting things to me is Andy Grove was one of the early founders of Intel. He wrote the book in the mid-1980s, and basically everything he proposes from a management perspective still rings true today.

5. What's a strategy to keep focused?
I try to only use pen and paper for most of the day. I leave my computer at my desk and my phone on my desk. At the beginning of the day I write things out on a paper calendar. I carry a notepad that acts as my to-do list and my appointments around with me all day. I found it makes me much less likely to be distracted during a meeting or checking email all the time. And it's helped my ability to focus on what I'm doing at any given time.

Related: She Was Told 'No' 100 Times. Now This 30-Year-Old Female Founder Runs a $1 Billion Business.

6. When you were a kid what did you want to be when you grew up? Why?
I knew I wanted to be some kind of entrepreneur or be my own boss. I also knew I wanted to do something involving the internet, because regardless of how old a person was or how much experience they had, you could use it to make something big that impacts people all around the world.

7. What did you learn from the worst boss you ever had?
I worked for a company that was really scattershot in the way they messaged the mission of the company and the product that they were building. I found that when I spent time talking to and interviewing people that were using the product, they all had a different idea of what the product was.

The company was gung-ho on building a company around an idea instead of what users wanted. It was clear from that experience that actually talking to the people you're building a product for is the most important thing you can do, and we weren't doing that at all. The company wasn't successful, and it's made me realize how important it is now to spend a lot of time with our learners figuring out what they're going through and trying to empathize with them.

8. Who has influenced you most when it comes to how you approach your work?
Our team. This is the first real job I've ever had. I dropped out of college to start the company. So I look at it as my job to hire and work with people that I can learn a lot from. [For example] I've never done marketing: what can I learn about marketing from the people on my team? I don't just go to work every day; I get to learn from people that I get to choose to have around me.

9. What's a trip that changed you?
The first time I went to Silicon Valley. It was when my co-founder and I applied to Y Combinator. We went out for an interview, and in the first 72 hours we met 20 different people that had started companies that were successful and were willing to help us. Seeing people paying was super impactful.

10. What inspires you?
I think what I started the company for, which was to give people skills and help them make more money in their careers and live better lives. We're lucky that we get that reinforcement cycle on a regular basis. I talk to our learners all the time. We have a Slack channel where we forward feedback to the entire company. Any time I'm having a not particularly good day, I can get into that Slack channel and read what our learners are saying about what they're taking from Codecademy and how it is changing their lives. That helps me get back on track.

Related: Shark Tank's Barbara Corcoran Explains Why You Must Make Time in Your Schedule For Fun

11. What was your first business idea and what did you do with it?
Designing iPod cases. I was 13 or 14 and someone had given me an iPod, and I was disappointed I had nothing to cover it with. So, I contacted a bunch of people that made phone cases and worked to make an early version of a waterproof iPod case.

12. What was an early job that taught you something important or useful?
Early on I worked at a tech startup and in order to get that job, I kept pestering the founder of the company. He came to speak on campus when I was at Columbia. I spent a lot of time sending him emails and getting coffee with him before ever getting the job. One of the most important things I learned from that was the importance of persistence. I'd been told "no" a bunch of times before he let me hang around the office. Finding a way to see if I could help from afar and demonstrating value upfront was something I think helped me. That job opened the door for a lot of other things I did.

13. What's the best advice you ever took?
It's okay to not know everything. Early on, I'd fixate on the fact that people would only work for someone who they thought knew more than them in a given subject area. I was 20 at the time when I started the company, so it was hard for me to know more than anyone. Ultimately, I realized being open and honest with my team about what I knew, what I didn't know and how I thought they could help was a better way of running a company.

14. What's the worst piece of advice you ever got?
It is common to think that you can spin [a difficult situation] whether it's related to someone leaving the company, a deal that didn't go through or a fundraising process that wasn't going well. We made transparency a core value at Codecademy and disregarded that advice pretty aggressively early on. In the end, it has paid dividends to be open and honest.

15. What's a productivity tip you swear by?
Ditching your phone during the day or putting it in Do Not Disturb. I took a vacation over the holidays this year where I checked my phone once a day and turned off most notifications. I ended up feeling much better was able to think much deeper. Since coming back, I've been leaving my phone on my desk while I work the entire day. I've been telling the people I work with that there's a hierarchy of communication. You can email me if you expect a longer-winded response. Slack me here if you're expecting a quick response in a couple of hours and text or call me if it's really important. Setting expectations like that has led people to communicate better and a lot of people have been doing the same thing.

Related: Health and Beauty Mogul Bobbi Brown Shares The Biggest Time Sucker -- and What You Can Do About It

16. Is there an app or tool you use in a surprising way to get things done or stay on track?
I use an app called Gyroscope that helps you stay on track with goals that you have. For me, I like working out a certain number of times a week, meditating or reading. Having a way to keep myself accountable has been helpful.

17. What does work-life balance mean to you?
It is more as an integration between the two. If I'm working all the time and not enjoying myself then there's a real problem. I need to understand how not to push it too far. And so for me, it's being super conscious if I've been working 18 hours a day for three weeks. I'm enjoying myself, but I need to sleep and prioritize. Making sure I'm ready to keep doing what I'm doing over the long term has helped me make sure I'm balancing things.

18. How do you prevent burnout?
One of the things that's helpful every morning is when I write down my priorities and to take a minute and think about how I feel. I just have to ask myself, are things going well? Are they not? What can I do about it?

19. When you're faced with a creativity block, what's your strategy to get innovating?
Travel is a big thing, and I do it alone. A couple of months ago I spent the weekend in upstate New York, reading and writing a bunch and thinking about the business. I also try to draw on a lot of sources, whether its talking to people or reading. It helps break up the day-to-day grind of reading emails and being stuck in meetings.

20. What are you learning now?
We launched a data analysis course in December, and I take almost all of our courses, so I'm in the middle of it. As a CEO, understanding the metrics of your company is super important. I have a pretty good grasp of that, but I'm learning more about how to go even a level deeper and understand what we're doing, how well we're doing it and how we can better help our learners.