Jan Koum is the founder of WhatsApp, which sold to Facebook for $22 billion in 2014. He self-taught himself to code using a bunch of used books, and overcame enormous personal odds before he ever started WhatsApp. His story, which began on the outskirts of Kiev, Ukraine, is a truly rags to riches tale. When Jan was growing up in Ukraine, his home had no hot water and little connection to the outside world. It did have a telephone, but his mother was afraid to use the phone because their family was Jewish, and Ukraine's secret police had a long history of antisemitic actions toward the jewish population.

In 1992, Jan immigrated with his mother and grandmother to Mountain View, California. He was 16 at the time, and the family stayed in a government sponsored two-bedroom apartment. Today Mountain View is a booming tech center, but in those days housing was still low-cost and somewhat prevalent. To put together enough money to survive, Jan's mother babysat and Jan swept supermarket floors. It was a hard life in a new country, but things would only get more difficult from there...

Jan's father - who was planning to join the family - fell ill before he could make the trip. He eventually died in 1997. Then Jan's mother was diagnosed with cancer (to which she would eventually succumb in 2000). The family was forced to rely on food stamps just to survive. Few people could fault Jan if his life began to unravel at this point. Immigrating to a new culture and country is hard enough, but when you lose your two parents in the span of 5 years, and you lift your head up and notice a world around you that doesn't add up... that's an unconceivable kind of pain. But Jan took the lumps as they came. When he was still in high school, he began to buy books from a used book store, and teach himself networking engineering. When he finished with the books, he'd return them and got his money back. He used his self-taught skills to land himself a job at Ernst & Young while still in university.

One of his first clients was then-fledgling but soon-to-be Internet search giant, Yahoo. After a short time with Jan, their team was so impressed by him, that they too offered him a job. And before he knew it, he was working with - among other Yahoo stars - Brian Acton, one of Yahoo's earliest employees.

Brian's earliest recollections of Jan impressed him the most: whereas Ernst & Young employees tended to be flowery speakers who knew how to tell you what you wanted to hear, Jan was blunt. He didn't have a penchant for bullsh**. He said it like it was and expected the same kind of bluntness back to him. For nine years Jan worked at Yahoo, through the enormous rise... and then through the slow, stuttering fall of the Internet giant. Eventually in 2007, he took a year off and travelled through south and central America. During this time, he applied for jobs both to Facebook and Twitter... and he was rejected. So he used about $400k in savings from Yahoo to start on a new Project: a messaging app that he called WhatsApp. He chose the name because he believed it was similar to the popular greeting, "What's up!" After building a base of about 250,000 active users, he brought old friend and colleague Brian Action aboard as a co-founder.

Together they took the journey to grow what is now one of the most captivating startup stories ever. Between 2009 and 2015 WhatsApp went from nonexistent to having over 900 million active users, and becoming the largest messaging app in the world. Additionally, it sold to Facebook for $22 billion in 2014.

When Jan signed the papers that would make him one of the richest men in the world, he didn't do it in the Four Seasons or at Facebook Headquarters, and he didn't have camera lights glaring. Instead, he returned to the nondescript building where he once stood for hours waiting with his mother for food stamps. There, out of the limelight, Jan penned his signature. In that moment he completed a circle that was about so much more than teaching himself computer networking skills from used books or even building a successful business: it was about turning the tables in his life and offering purpose and meaning to even the hardest of times.

Credit: http://www.wearobo.com/2015/12/the-story-of-most-successful-self.html#sthash.5iEN0SXg.dpuf