Let's start by saying this: there's nothing wrong with business school or higher education. Everyone should have an opportunity to pursue education and earn a degree in whatever field of study interests them. But, formal education is not always the answer. Book smarts do not always translate to street smarts. In the tech world, where it's difficult to predict what will be a flash in the pan and what will turn into the next billion dollar business, most entrepreneurs rely on experience and firsthand knowledge to be successful.

Valuable Lessons from Tech Entrepreneurs

If you've ever seen the movie Fight Club, you may remember the quote, "How much can you know about yourself if you've never been in a fight?" While Brad Pitt's character is literally talking about hand-to-hand combat, that quote resonates with people for other reasons. In the tech industry you could ask, "How much can you really know if you've only ever read a text book?"

While nothing substitutes for hands-on learning, let's take a look at six lessons you can learn from tech entrepreneurs who've been through valuable experiences and trying situations.

Limitations are Self-Imposed

The large majority of limitations on personal growth are self-imposed--at least that's what ultra-successful entrepreneur Mark Cuban believes. While he's now known for his involvement with the popular show Shark Tank and ownership of the NBA's Dallas Mavericks, Cuban first made a name for himself when he sold his first company to Yahoo for $5.7 billion in 1999.

Things weren't always simple for Cuban, though. There was a time when excuses held him back. Ultimately, he learned that if he stopped making these excuses, buckled down, and started working hard that, "with time and effort I could learn any new technology that was released." Are you self-imposing limitations on yourself?

Customer Validation is Crucial to Success

If you ask Paul Nichols, a successful tech entrepreneur who's been a CEO, venture capitalist, and business coach, customer validation is worth its weight in gold. "High failure rates are well known for this field and of course none of us plan on being one of the grim statistics," he writes. "But the number one reason for startup failures is a lack of market information and intelligence."

Nichols tells everyone just how important customer validation and market insights are. As a young tech entrepreneur, you can't blindly proceed with an idea unless you've seen some proof that the market will accept it. "No oil developer ever drills a well without thoroughly mapping out the ground beforehand," he points out. So why would you?

Don't Take Things Personal

Keeping your business endeavors and your personal life separate from one another is harder than it sounds, but extremely important. "Don't let business get personal," says inventor and successful entrepreneur Lorie Greiner. "It's just business. Shrug it off." She tells people this all the time, recalling an early moment in her career when she was overlooked by someone and angrily stormed out.

There has to be some separation between your work and your personal life, or you'll be a chronic mess of stress and anxiety. If you want to make this happen, you have to stop identifying yourself with your business. Sure, your ventures are important to you, but they don't define you. Whether someone praises or slams your business, don't take it personal.

Courage Can Take You Anywhere

The late Steve Jobs gave some fantastic quotes during his lifetime, but few standout more than the following: "Have the courage to follow your heart and intuition. Everything else is secondary." He told this to the Stanford graduating class of 2005.

While it may sound like a fairy-tale like quote at first, it actually has some really practical value in it. So often, tech entrepreneurs get caught up in the technical aspects of a product or venture and fail to follow their intuition. When something feels right, it's okay to chase it. (But do Nichols a favor and get a little customer validation first).

Surround Yourself with the Right People

Successful young entrepreneur Brienne Ghafourifar says, "A supportive ecosystem is extremely important." Have you ever considered who you're surrounding yourself with and what impact they have on your entrepreneurial success? For example, are people constantly raising their eyebrows and doubting your dreams, or are they encouraging you by offering critical advice.

Whether you like it or not, you become like the people you spend time with. You won't morph into a clone of them, but you will pick up attributes and characteristics. Your future is too valuable to risk surrounding yourself with negative personalities. Carefully evaluate this aspect of your life.

Never Feel Too Important

Even after you successfully launch a company and have earned the right to tell people what to do, you can't look at yourself as better than anyone else. According to Walter Knapp, CEO of Sovrn Holdings Inc., it's important to take on menial tasks in order to keep yourself grounded and show those around you that you're on their level. He says his father taught him what being a successful professional is by always picking up the trash at his own company.

"An owner picks up the trash," Knapp says. "Even though he owned the clinic, he'd be the first guy to pick up an empty soda can in the parking lot." As an entrepreneur or owner of a successful startup, you have to be willing to do the same.

Learn from the Best

While there's a ton of value in reading textbooks and working through problems, it's important to learn from those who've been before you. As you progress through your career, remember these six quotes from successful tech entrepreneurs.