A 'defining moment' in Howard Schultz's life came as a 7-year-old in the projects watching his father after he was maimed in an accident

Billionaire Starbucks Chairman Howard Schultz opened up on Monday in a commencement speech at Arizona State University about the hardships he endured growing up in public housing in Brooklyn, New York.

Schultz, who received an honorary doctor of humane letters degree during the ceremony, told the audience of more than 30,000 that when he was a child, his parents, both high school dropouts, struggled to pay their $96-a-month rent while working blue-collar jobs.

In March 1960, Schultz came home from school to find his father "laying on the couch with a cast from his hip to his ankle" after being injured on the job. He was an army vet and a truck driver with no workman's compensation, no severance, and no health insurance, Schultz said.

"When I was seven years old, I had a defining moment in my life," he said. "I saw the fracturing of the American Dream and I saw my parents go through hopelessness and despair ... And those scars, that shame, that is with me even today."

But, Schultz continued, his mother taught him that "good education and hard work will open the doors to a better life." This belief, coupled with Schultz's fortitude and perseverance, led him to build one of the most valuable and respected brands in the world today.

Starbucks now has 26,000 stores in 75 countries, and employs more than 300,000 people, he said.

"I stand before you as living proof of the American Dream," said Schultz, whose current net worth is around $3 billion. "From day one, I really wanted to build the kind of company my father never got a chance to work for. A company that honors and respects the dignity of work. And the dignity of all men and all women."

Schultz said his father's experience inspired his decision 30 years ago to provide all Starbucks' employees — even those who worked part-time — with comprehensive health insurance.

"That provides me with an important lesson to share with you all today: That your station in life does not define you and the promise of America. That is for all of us," he told the graduates.

In 2014, Schultz launched a groundbreaking program offering tuition reimbursement to Starbucks employees, also known as partners, who want to earn a bachelor's degree through ASU. More than 9,300 partners, including part-time workers, have enrolled in the Starbucks College Achievement Plan, according to ASU, and 330 graduated on Monday.

"It is my firm belief that success in business and in life is best when it's shared," said Schultz, who stepped down as CEO of Starbucks in April and now serves as the company's executive chairman. "Only in America can a poor kid from public housing have the privilege and the honor to be the commencement speaker at the largest and most innovative university in the country."