What Mark Cuban Learned From His 6 Biggest Failures Forget your failures. No one cares until you succeed.

It's easy to imagine Mark Cuban behind a desk, on television or courtside at a Mavericks' game. It's more difficult to imagine him fumbling a carpentry job, failing to pay his electrical bills or being on the receiving end of a firing. But Cuban, like everyone else, started somewhere. And he was once laying down carpets instead of million dollar investments.

Currently worth $3.4 billion, Cuban's massive achievements came on the heels of many failures, all of which were valuable -- even if painful -- learning experiences.

His story goes to show that sometimes you have to lose 20 times or more before winning big, and what seems like luck is really just grit. Here are six of Cuban's biggest failures and what we can learn from them:

1. When he couldn't learn a fall-back trade

While growing up in Pittsburgh, Cuban's parents encouraged him to learn a trade should he ever need a job to fall back on. Practical advice, except for one small problem. Cuban was pretty bad at most of the jobs he took on.

He worked as a carpenter laying down carpet, and quickly discovered he was terrible at it. As a short-order cook, he could only tell when food was ready by sampling it. And as a server, he struggled to open wine bottles without getting corks in diners' Merlots.

Lesson learned: It's okay not to be great at everything. "I've learned that it doesn't matter how many times you failed," Cuban says. "You only have to be right once."

Related: Faced With Failure, This Founder Could Have Given Up -- But Instead He Started Over

2. When his powdered milk gig held no water

Fresh out of business school at Indiana University, Cuban left his first job at a PC store because "they didn't see a future in computers." Set on starting his own business instead, Cuban's very first venture was not destined to be the big break he'd hoped for.

The idea? Powdered milk. He saw an ad for the product and thought everyone needs milk. It's cost effective and tastes about the same -- why not go for it? As it turned out, his parents were among his only customers. "I honestly thought it would make a killer business," Cuban recalls, "and it lasted minutes."

The lesson? Don't misjudge the market or the product. There's a reason real milk reigns supreme, and judging by your tastes alone isn't enough to launch something sustainable.

3. When being fired from a software job hardened his ambitions

After making a big move to Dallas, Cuban landed his first sales job at a company called Your Business Software. Knowing little about software, he taught himself on the job by reading all the manuals and went the extra mile to secure new customers.

But his initiative wasn't enough to stop him from getting fired less than a year later. In fact, it was his initiative that would be his undoing. He closed a big deal with a client, and called out of his opening shift to do so against the CEO's wishes. When he returned to the office with a $1,500 check, he was fired.

For Cuban, this incident made clear to him why he wanted to start his own business. It's also why the CEO who fired him became his reverse-mentor. Says Cuban, "Even now I think back to things he did, and I do the opposite."

Related: 3 Lessons I've Learned After Being Fired 3 Times

4. When he couldn't afford to pay his bills

Cuban was once asked what he thought was the one thing all successful entrepreneurs should experience. "Coming home and having the lights turned off because you couldn't afford to pay the bills," he answered. "It's incredibly motivating and humbling."

He's also admitted to Entrepreneur to having his card cut up on one occasion. For Cuban, the lesson was simple. Use the shame and pain of such failures as a motivator to get back up and start winning.

5. When an NBA star reached huge heights without him

Cuban did eventually get his big break when started MicroSolutions and later sold it for $6 million, the first of his many lucrative business transactions. By 2000, he was even able to buy a majority stake of the Dallas Mavericks.

As owner, the Mavericks went from a 40 percent win rate to a 69 percent win rate. But even then, Cuban was not immune to failure. His biggest mistake was failing to re-sign Steve Nash, who left the Mavs to join the Suns and win MVP awards in back-to-back seasons. It was a terrible flaw in judgement, according to Cuban. "We certainly didn't see him as a two-time MVP. And it was the biggest mistake I made not re-signing him," he told Fort Worth Star-Telegram. "We thought his body would break down and it certainly didn't. So, bad advice, bad across the board."

The lesson? Don't take bad advice, hold onto your assets, and don't underestimate what talented people can accomplish with or without you.

Related: Why There's No Better Time Than the Present to Follow Your Dreams

6. When his first TV show flopped

Mark Cuban would go on to be the wealthiest shark on ABC's Shark Tank as of 2012. But it was not his first reality TV rodeo, so to speak. The first, called The Benefactor, was a flop. The 2004 series involved 16 contestants vying for a $1 million prize, with Cuban judging their performances. Due to poor ratings, it was cancelled before the first season aired.

It's just another example of the old "if at first you don't succeed" adage, and for Cuban, it worked. Shark Tank is now the most-watched program on Friday nights for viewers aged 18-49.

If at first you don't succeed …

As Cuban wrote in his book, "It doesn't matter how many times you almost get it right. No one is going to know or care about your failures, and neither should you." When you finally get it right, "then everyone can tell you how lucky you are."