The president and chief operating officer of another one of Musk's companies, SpaceX, who's worked with the iconic entrepreneur for more than a decade-and-a-half recently shared her experience.

"I love working for Elon. I've been doing it for 16 years this year, actually," Shotwell says in an TED talk in April.

"I don't think I'm dumb enough to do something for 16 years that I don't like doing. He's funny and fundamentally, without him saying anything, he drives you to do your best work. He doesn't have to say a word. You just want to do great work," says Shotwell.

He pushes his teams to work on ambitious schedules, she says.

"There's no question that Elon is very aggressive on his timelines, but frankly, that drives us to do things better and faster," Shotwell says. "I think all the time and all the money in the world does not yield the best solution, and so putting that pressure on the team to move quickly is really important."

(Indeed, Musk's Tesla is infamous for missing production targets, most recently for its Model 3 cars. In an April interview with Gayle King, host of "CBS This Morning," Musk took responsibility: "I need to figure out how to be better…. And then we can be better at meeting goals," he said.)

But when Musk first articulates a goal, Shotwell says she listens and thinks before responding.

"I love working for @elonmusk... Without him saying anything, he drives you to do your best work. He doesn't have to say a word. You just want to do great work." — @SpaceX COO Gwynne Shotwell

"First of all, when Elon says something, you have to pause and not immediately blurt out, 'Well, that's impossible,' or, 'There's no way we're going to do that. I don't know how.' So you zip it, and you think about it, and you find ways to get that done," says Shotwell.

She has also had to get used to the idea is will never be easy going at SpaceX.

"I always felt like my job was to take these ideas and kind of turn them into company goals, make them achievable, and kind of roll the company over from this steep slope, get it comfortable," says Shotwell.