Bert and John Jacobs struggled to sell T-shirts out of a van for years before they discovered the power of an optimistic message. Life is Good What are we going to do with our lives?

That's the question Bert and John Jacobs were trying to answer when they decided to take a seven-week road trip from California to Boston in 1988.

The brothers — 20 and 23 at the time — say that the trip forever changed their lives.

John, who has since founded the Life is Good apparel company with his brother, tells Business Insider that it was during the road trip that he and Bert decided to pursue a new — and less traditional — career path: selling T-shirts.

They initially named their company Jacob's Gallery, and tirelessly traveled up and down the East Coast selling shirts to college kids out of their used Plymouth Voyager. But the business struggled, and at one point the brothers has just $78 in the bank.

But everything changed when they added an optimistic message to their shirts in 1994.

"We were searching for so many years for, 'What do we stand for?'" John says. "Then when we put out this new design, the response was so immediate. It was exactly what we had hoped for."

They rebranded and relaunched their company under the name Life Is Good, and within three years, they broke $1 million in sales. Now they're up to $100 million — selling their products in about 4,500 retail stores.

Here's the story of how these brothers went from running a struggling business to a successful one: