I like to write about failure, because it’s an integral part of success. Every one of my clients has succeeded, but only after a failure or multiple failures. We read about these mega-successful companies but sometimes don’t know about the failures these owners and founders dealt with along the way.

At the age of 39, Nick Woodman is a billionaire. He founded GoPro, a digital camcorder company recently valued at more than $3 billion. But before becoming one of the youngest self-made billionaires in the country, he had two companies that failed. His first was a site that sold electronics called EmpowerAll.com. It never got off the ground.

He did raise a lot of money for Funbug, a gaming site he started in 1999. But it went nowhere and shut down in April 2001. After coming up with the concept to attach cameras to athletes’ wrists, he launched his first device in 2009. Sales in 2013 were $985 million.

Jack Dorsey always loved computers and after working in dispatching services, came to value the ability to send short messages. He started a taxi dispatching service that worked through a website. But that company failed during the dot com crash.

He took that concept of short messages and used it to co-found Twitter, now one of the most popular social media sites in the world. One of his rules of success is “Fail Openly.” Oh, and also have an amazing haircut.

In an essay for the Wall Street Journal, “Dilbert” creator Scott Adams says his secret of success is failure. Before he achieved success with his comic strip he had several failures. These include his invention of a rosin bag that would attach to tennis shorts with Velcro. Turned out nobody wanted it and he couldn’t patent it.

He created “Dilbert” while working at a bank. He had drawn cartoons to liven up his presentations. After trying on and off unsuccessfully to get “Dilbert” into magazines and newspapers, he finally published the cartoon with United Media in 1989, becoming a full-time cartoonist of the popular cartoon in 1995.

In 2000, at the age of 22 Ben Huh started Raydium, a software analytics company. He managed to get investment money but a year later funds ran out and he couldn’t meet payroll.

But he didn’t lose his sense of humor and six years later, bought I Can Haz Cheeseburger. This odd sounding blog network, which is also the home of LOLcat, has been wildly successful, with half a billion page views a month. Investors were impressed enough to invest $30 million in this site of jokes about cats and other funny blogs in 2011.

The thing to remember is that these people learned something valuable from each failure that spurred them on and allowed them to ultimately become extremely successful.

Nick Woodman claims that it’s his fear of failing again that caused him to work 18-hour days to make GoPro a success, referring to it as “constructive fear.” In an article on Forbes.com, he said, “I was so afraid that GoPro was going to go away like Funbug that I would work my ass off. That’s what the first boom and bust did for me. I was so scared that I would fail again that I was totally committed to succeed.”

Failure is not a barrier to success. It’s merely a step. As Scott Adams said, “Success is entirely accessible, even if you happen to be a huge screw-up 95% of the time.”

That’s what life is really about — learning from our mistakes.