Elon Musk is well known for setting ambitious targets for his companies. In the end, though, he has a pattern of falling short of many of those goals.

Tesla has missed more than 20 production and financial targets in the past five years, according to a report from the The Wall Street Journal. The company missed 10 of those goals by an average of almost a year.

In May, Musk said he planned on delivering 17,000 cars to customers in the second quarter. In July, Tesla announced it had delivered 14,370, missing its target by 15 percent.

The much-hyped $35,000 Model 3 sedan, which is currently slated to launch next year, originally had a target rollout of 2014. And even 2017 might be ambitious: Musk recently said he doesn't expect production to start by July 1 of next year.

Earlier this month, the billionaire entrepreneur announced another set of lofty goals. He said he wants to increase Tesla's weekly output by 50 percent in the second half of 2016 compared to the first half. And he wants to produce one million cars per year by the end of 2020. In total, Tesla has sold about 140,000 cars since 2008.

Yet, while other chief execs would pay a price for missing goals, shares of Tesla are up 760 percent in the past five years. This shows, the Journal suggests, that Musk, like the highest-profile entrepreneurs in Silicon Valley, plays by a different set of rules than most when it comes to Wall Street.

"This guy wants to save the world," Ron Baron, founder of Baron Capital Group Inc., which has more than $300 million invested in Tesla, told the Journal. "The odds are very favorable that we are going to make a lot of money on this investment."

Musk's bold goals don't apply only to Tesla's production numbers. He has been very vocal about wanting to send private missions to Mars by 2018. And he recently pushed the completion date for Tesla's massive battery Gigafactory from 2020 to early 2017, and doubled the size of the force working on its construction.

To pursue his ambitions, Musk is known for taking ruthless measures. A 2015 biography features details about Musk's disdain for vacations and his belief that not enough of his employees were working on weekends. And earlier this year, according to the Journal, he gave his engineers aggressive specifications on door molding for Tesla's Model X cars. When he noticed a door seal hanging off one of the vehicles, Musk held a meeting, received an explanation from director of product excellence Chris Van Wert, then escorted him out of the meeting. Van Wert is no longer with the company.

Musk's habit of announcing his high expectations to the world certainly grabs headlines--and probably is intended to set expectations for employees as well. But he insists that his goals are based on reality. A public company can be held liable for forecasting targets that it knows it has no chance of meeting, but Musk says this isn't the case. "I have never set a goal which I know is unrealistic, unless I have specifically said I know it's unrealistic," Musk said in an interview with the Journal.