Mark Cuban is an avid reader (as are his fellow billionaires Bill Gates and Warren Buffett). In fact, Cuban has said his curiosity and constant learning have been key to his success in business
But Cuban said one book in particular stands out as helping him to stay focused on his money goals early in his career: "Cashing in on the American Dream: How to Retire at 35."
The 1988 book by Paul Terhorst, an accountant-turned-author, details how he was able to retire at age 35. The premise of the book is that "if you could save up to $1 million and live like a student, you could retire," Cuban told CNN Money in 2017. Terhorst prescribed spending no more than $50 a day (the equivalent to around $110 today).
After reading it, Cuban was determined to save every penny he could.
"To me, my goal was to retire because I wanted my time to myself," Cuban told couple Alli Webb, co-founder of Drybar, and leadership coach Adrian Koehler on a recent "Raising The Bar" podcast, when talking about reading the book as a young man.
"That's the one thing you don't get a second shot at. And I was willing to give up a lot to get there."
To save money and help reach his goal, Cuban said that in the late '80s and '90s, he lived off of macaroni and cheese and drove "the worst possible car." (First Cuban had a Fiat X1/9 with a hole in the floorboard and later a 1966 Buick LeSabre, he told CNN.)
Though Cuban's original goal may have been to retire early, even after he became rich, he never stopped working. In 1990, Cuban sold MicroSolutions to CompuServe for $6 million; in 1999 he sold Broadcast.com, to Yahoo for $5.7 billion in stock; and in 2000, Cuban became a majority stakeholder in the NBA's Dallas Mavericks.
Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank."