In high school, Elon Musk planned to pursue a career in physics. But then, in 1993, Congress voted to pull funding from the Superconducting Super Collider, which had been under construction in Texas for about 10 years. That event made a deep impression on Musk and set him on the career path he's still traveling today.

"When I was in high school, I thought I'd most likely be doing physics at a particle accelerator," Musk said in a recent Third Row Tesla podcast. "I got distinctions in two areas, physics and computer science. Those were my two best subjects, and I thought, OK, I want to figure out what's the nature of the universe and so go try to work with people banging particles together and see what happens."

Accordingly, Musk, who had started life in South Africa and then emigrated to Canada, attended the University of Pennsylvania where he majored in physics and economics. But then came the cancellation of the Superconducting Super Collider, a victim of budget overruns and spending on the International Space Station, since many in government believed that the country could not afford both. That event had a big effect on Musk's career plans. 

"That was like, whoa!" he said. "What if I was working at a collider, spent all these years, and then the government just canceled it? No, I couldn't do that." 

Forget the PhD. Become a founder instead

Musk was accepted into a PhD program in energy, physics, and material science at Stanford, but he decided not to go, because he'd had another revelation while in college. "The internet would fundamentally change humanity. Humanity would become more of a superorganism," he said. (A superorganism is a large number of organisms working together as one. Think of ants, or the Borg in Star Trek.) The internet would function as humanity's nervous system, he foresaw, allowing the whole species to share knowledge. So instead of getting his PhD or working at a particle accelerator, Musk, along with his brother Kimbal, founded his first internet startup, Zip2, which made online city guide software that was sold to newspapers. Compaq acquired Zip2 in 1999 and Musk walked away with $22 million.

In 1999, he co-founded X.com, a financial services and email payment company, which later merged with the parent company of PayPal. Musk became PayPal CEO but then lost that job over a conflict with other leaders over moving the company from Unix-based servers to Windows servers. Still, he remained on the board and owned 11.7 percent of the company's stock when it was acquired by eBay in 2002. This time, Musk made $165 million.

That same year, he founded SpaceX, and in 2004, he led the series A funding round for  Tesla (which had three employees at the time). In 2008, he became Tesla's CEO, a position he still holds, making him the longest-tenured automotive CEO working today

Musk's successes all result from a single realization at an early age: Being an entrepreneur was the only way he could be master of his own fate. Musk has had his setbacks -- he was forced out as CEO of PayPal. He was  disciplined by the SEC and forced to step down as Tesla's chairman. He endured years of  Wall Street disdain of Tesla, with critics claiming it would never amount to anything. But all of those were his own setbacks, the results of his own decisions and not, say, Congress's vote to defund a project after spending 10 years and nearly $2 billion on it.

Musk could have gone to work for a company, rather than a government-funded project, but as he likely realized, he'd have been just as subject to the whims of those above him in the hierarchy. Consider what could have happened if Musk, who had a longstanding concern over fossil fuels and thus an interest in designing electric car batteries, had sought a job in the automotive sector instead of starting his own venture. He might have ended up working on General Motors' beloved electric car, the EV1, launched in 1996. GM decided to repossess and crush them all three years later.

Being an entrepreneur comes with lots of risks. But you won't risk having to junk a good idea because of someone else's questionable decision. That's something to consider if you're trying to decide whether to work for someone else or be your own boss.