There’s a lot we can learn about building brands and growing successful startups from CEOs who have been there and done that. Countless interviews with the best in tech have helped budding entrepreneurs and even everyday workers to be inspired with what they do. But sometimes, it’s what the vast majority of the public doesn’t know about CEOs that can be most interesting of all.

It’s not just about how these CEOs run their businesses that’s so important, but also what they did before they became millionaires, and what their personal experiences were like growing up. Here, we’ve rounded up some interesting facts about CEOs in the tech industry that are well worth a read:

Brian Chesky, Joe Gebbia, Nathan Blecharkzyk – Airbnb

Dedicated entrepreneurs will stop at nothing to get their startups off the ground, and are ruthless in their attempts to do so. Of course, one of the biggest issues startups face is lack of capital. When Airbnb founders Brian Chesky, Joe Gebbia, and Nathan Blecharkzyk ran out of money, they had to get creative with coming up with the funds to continue operating.

The result? They took advantage of the 2008 presidential election and ordered 1,000 boxes of election-themed cereal. One box was called Cap N’ McCain and bore a caricature of John McCain, and another called Obama O’s, showed a cartoon-style photo of Barack Obama. They priced the limited edition boxes at $40 each, and sold out all 1,000 boxes.

They then used the $20,000 profit to funnel back into the business. Paul Graham was so impressed with the founders’ dedication and innovation that he accepted them into Y Combinator, the world’s most exclusive startup incubator. Without the cereal boxes, the founders may never have been accepted into Y Combinator, which spearheaded their success; as a result, it’s safe to say that Airbnb was funded through boxes of cereal.

Charles Phillips – Infor

Charles Phillips, the CEO of Infor, was making $3.2 million annually in 2012– and before that, $30 million per year at Oracle. Phillip’s rigid background in the military has helped him grow Infor to the corporation it is today — while still maintaining the entrepreneurial, startup spirit at Infor.

And still, Phillips revealed to Business Insider that he commuted to work via subway. Even more surprising is that, unlike most CEOs the multi-million dollar bracket, he answers his own emails. While these are simple tasks to the everyday employee, they aren’t in the business world.

It’s always flattering when you’re compared to someone who made great strides in a particular industry, and because of Phillips habits and qualities, he’s been compared to the late Steve Jobs.

Jobs was also one of the few CEOs who answered his own email, and like Jobs, Phillips also approves every design detail before implementing it. As a result, Infor has been able to stand out from competitors (traditional ERP systems aren’t very attractive) and offers software options with unique designs exclusive to certain industries.

Jeff Bezos – Amazon

One thing many people may not know about Jeff Bezos is that he left a world of financial security when he quit D. E. Shaw, an investment management firm on Wall Street, to create Amazon. He spent several months researching and writing a business plan for Amazon, though a positive reward was never guaranteed.

Durings its early days, Bezos toyed with many different ideas until he finally found something that stuck. For example, Amazon was originally named Cadabra, and then later Relentless. And when the website finally first launched, it only sold books. Their claim as “Earth’s Largest Bookstore” resulted in a lawsuit with Barnes & Nobles, but that was later settled. And when the company first got started, they rang a bell each time a purchase was made on the site. Today, that would be a lot of bells.

Mark Zuckerberg – Facebook

Mark Zuckerberg is one of the most popular people in the world, and it’s because of this that much of his life has been put on the spotlight. Still, there are some things about the Facebook founder that aren’t in most books and movies. For example, many don’t know that a large part of the reason Facebook’s logo is blue is because Zuckerberg has red-green color-blindness.

And while it might seem like Zuckerberg was born coding, he actually learned how to code using the C++ Coding For Dummies book and through conversations with friends. He originally attended Harvard to study classics, and while he tinkered with inventing things in the past, he hadn’t formally been interested in computer science until college.

Although Facebook is the ultimate collector of information, Zuckerberg is ironically big on personal privacy. He purchased a 700-acre plot of land in Hawaii, and even attempted to have four homes surrounding his property in California demolished — all in the name of privacy.