Michael Kirban has something to prove. Kirban, the 37-year-old co-founder and CEO of Vita Coco, had learning disabilities as a child. He spent half his school day in regular classes and half in special ed, which the other kids mockingly dubbed "romper room." Later, after Kirban dropped out of college and told friends he was starting a coconut-water business, some of them laughed. He chose to listen instead to his father, who always advised, "Don't listen to the 'What are you, nuts?' people."

Coconut water is now one of the country's fastest-growing beverages, and Vita Coco is the top-selling brand, with nearly $100 million in sales last year. The New York City--based company has a market share of about 50 percent, more than the combined shares of the next two brands, which are owned by Coca-Cola and PepsiCo. Around the office, Kirban is known to fire off quick decisions, hire people because of their attitude, and spend a fair amount of time in the office hammock. He explained the way he works to Reshma Yaqub.

Thanks to my insomnia and my 2-year-old daughter, my workday starts at around 5:30 a.m. I make a triple espresso, and my daughter usually sits in my lap while I chat on Skype. We have offices in four countries now, in four time zones. We're producing coconut water in a dozen facilities, in South America and Southeast Asia. Plus, sales are growing in Europe, and we're thinking about expanding to Japan. So I use Skype a lot, and I have to adjust my schedule to be available to everyone.

By 7:30, my wife, Arianna, is buzzing around the apartment, and I hand off my daughter with a big kiss. Then I head to the gym for an hour. Working out is very important to me. It's less about staying in shape and more about stress release. Right now, my routine consists of a Marine-style workout and boxing.

At 9, I walk half a block from my apartment to my office in the Flatiron District of Manhattan. I like having such a short commute, because I can visit my family during the day. When the weather's good, my wife and I take our daughter for a stroll around the block. I can still be back at the office in 20 minutes or less.

I spend the first hour at work bouncing around the office and talking to people. I would describe my style as management by walking around. I like to pop in and out of meetings that are going on, and drop in and out of conference calls. Often, the people on the other end of the call won't even know I was there.

Three years ago, we were 18 people. Now we're 150. All the employees here are really nice people. I hire based on attitude, not what school somebody went to. And everyone here is personally invested; they've all got either shares or stock options. I've always admired companies that make not just the owners rich, but the employees, too.

My co-founder, Ira Liran, and I own the largest share of the company. We also have some celebrity investors, such as Madonna and Spike Lee, who liked the product and approached us. All the celebrities paid for their shares. I don't give away free equity.

About a quarter of my time is spent traveling. I meet with our distributors and sales teams around the world, and I travel to our factories. Though most of our factories are automated, in Brazil it's still a bunch of guys with knives opening each and every coconut by hand.

The reason I started this company was just to earn some extra money to fund my travels. Ira and I have been friends since we were kids. We got the idea for Vita Coco after meeting some Brazilian girls in a bar. They kept talking about how much they missed coconut water, which was big in their country. Ira ended up marrying one of those girls.

Every day, I meet with my direct reports--the CFO, the vice presidents of sales and marketing, and the director of operations. I had no experience in the beverage industry before I started this company, so it has been important for me to surround myself with people who do have experience. That said, my inexperience has served me well. I make decisions that an insider might be too cautious to make. Some people thought it was crazy when I decided to build factories when we were just an $8 million company. I'm able to do creative things because I don't already believe that they can't be done. I'm good at making decisions very quickly. I think it's better to take risks than to be perfect. And if something doesn't work out, I don't look back and say, "Oh, what if..."

I'm kind of a control freak. But in the past year, I've gotten a lot better at delegating. I'm finally trusting key people around me to take on more responsibility and make decisions without running every little thing by me. And you know what? Things are actually working better. Before I hired my vice president of sales last year, I was spending 50 percent of my day just on sales.

When I'm in meetings, I can be incredibly focused and a little bit all over the place. I never sit in a chair for very long. So if I'm in our conference room, I will bounce from the windowsill to a desk chair to a beach chair that I keep in there.

I take some meetings in the office chill-out room, which has a hammock. I spend an hour a day in that hammock, just listening to employee presentations and updates. Being in the hammock keeps me focused, because I can't look at my computer. The hammock is one of my hiding places, too. Our office is a very open, free-flowing, interactive place. When I need to escape--to read a contract or just have my own space--I climb into the hammock.

I spend a lot of time thinking about how to protect and nurture this brand. As recently as 2009, some big retail chains took a lot of convincing to carry coconut water. These days, it's more about pacing the brand's growth and making sure we're in the right stores in the right locations. We also want to separate our product from the rest of the players in the category. Beating Coke and Pepsi is, more than anything, what drives me to work hard. My goal is to get 70 percent of market share this year.

At some point, I like to get out of the office during the day and walk around town. I go into local delis and check on our displays. In a store, if I see people looking through the beverage aisle, I buy them a Vita Coco. I will literally walk them to the cash register and pay for it. When I see someone on the street drinking Vita Coco, I go up and ask them how they like it. A lot of women think I'm hitting on them. Actually, a lot of men think I'm hitting on them, too.

I leave the office no later than 6:30 p.m. We live near Eataly, a large Italian market, so sometimes I'll pick up some beautiful cheeses to have with dinner. I usually enjoy a good hour of playtime with my daughter before her bedtime. After my wife and I have dinner and relax a bit, I prepare myself for 15 to 30 minutes of e-mail with Asia. It's the start of their day and the end of mine.