Jim Koch left a comfortable career with the Boston Consulting Group in 1984 to start the Boston Beer Company with its flagship product, Samuel Adams Boston Lager.
Although the beer was Koch's version of his great-great-grandfather's recipe, even his brewmaster father thought the idea of competing in a market with companies like Budweiser and Heineken was destined to fail.
But through extensive distributor outreach and marketing, Koch's company helped Americans embrace craft beer. Today the Boston Beer Company produces an estimated 1% of the beer in the US, and it had a record year in 2014, bringing in $903 million in revenue.
Koch has also run the Brewing the American Dream initiative since 2008. The program offers entrepreneurs in the food and beverage and hospitality industries free business coaching sessions and the opportunity to apply for loans.
He says that he most frequently reminds entrepreneurs to "pursue something you love."
"A small business is going to be very demanding of your time, your energy — it just eats your life," Koch tells Business Insider. "And if you're doing something you love, then you will accept and even enjoy that. If you're just doing it to get rich, you're gonna lose heart."
Koch became a billionaire in 2013. He says that while he appreciates the success of his company, he doesn't think too much about his net worth.
"I tell everyone, getting rich is life's biggest booby trap," he says.
Koch believes achieving wealth brings the temptation to sacrifice your passion for whatever will result in more cash, and using wealth as your main motivator sets you up for self-destruction.
"It comes down to what would you rather be, happy or rich?" he says. "I say do what's gonna make you happy."
NOW WATCH: 7 Classic Beer Combos Everyone Should Try
See Also:How the Coke bottle got its iconic shapeThe funny reason Under Armour decided to use the British spellingWhy companies use interim CEOs — and why they're usually a bad idea
SEE ALSO: Billionaire Sam Adams founder on how he helped spark the craft-beer revolution