Bad bosses leave mark on billionaire

After graduating college, Mark Cuban got a job at Mellon Bank. His youthful energy led him to think like an entrepreneur—and that landed him in trouble with higher-ups.

At first, his actions seemed harmless. He wrote notes to the CEO suggesting ways the bank could cut costs. He launched a “Rookie Club” that connected new hires in their 20s to senior executives.

Then he started writing an internal newsletter updating employees on various projects.

Cuban figured his boss would approve of his initiative. Instead, his manager called Cuban into his office and said, “If you ever go over me or around me, I’ll crush you.”

The future billionaire quit his bank job, moved to Dallas and landed a sales position at a software firm. After nine months, he was about to make his biggest sale yet—for $15,000—when he alerted his boss of the good news.

“I thought he’d be thrilled,” Cuban recalls. “He wasn’t.”

Cuban didn’t understand why his manager, Michael, sought to forbid him from closing the huge sale, so he went ahead with it. When he returned to the office with a $15,000 check, he assumed Michael would come around.

But Cuban was fired. Michael resented that Cuban failed to follow orders, even though the rationale for the orders was fuzzy at best.

At age 25, Cuban decided to start his own business. As he gained success, he viewed Michael as a kind of guidepost.

“Even now I think back to things he did, and I do the opposite,” Cuban writes. Today, he owns the NBA’s Dallas Mavericks.

— Adapted from “At Age 25, Mark Cuban Learned Lessons About Leadership That Changed His Life,” Mark Cuban,