Elon Musk is Time magazine's person of the year for 2021. The choice seems like a no-brainer, given everything Musk has done. There's one personality trait, or one bit of knowledge, that explains why Musk has upended four industries so far--banking, automotive, aerospace, and solar. He knows time is limited, both for humanity and for him personally, and he's driven to make every moment of his life count.

In naming Musk person of the year, the Time writers describe him this way:

"This is the man who aspires to save our planet and get us a new one to inhabit: clown, genius, edgelord, visionary, industrialist, showman, cad; a madcap hybrid of Thomas Edison, P.T. Barnum, Andrew Carnegie and Watchmen's Doctor Manhattan, the brooding, blue-skinned man-god who invents electric cars and moves to Mars." 

Which sums him up pretty well. Musk has been an icon for many years but earned Time's top honor this year because he's in ascendance: Tesla, valued at about $1 trillion, is by far the world's most valuable car maker, and it's continued to increase production while other automakers fell victim to the chip shortage. Meantime, demand for Tesla's Powerwall batteries, which can store solar-generated power, is growing rapidly. NASA gave SpaceX an exclusive contract to take astronauts to the moon, and used its rockets to test a brand-new system that could one day protect Earth from incoming asteroids. Not only that, but he got to host Saturday Night Live, and used the occasion to reveal to the world that he has Asperger's syndrome.

Musk clearly is a genius and a polymath, but what's so fascinating about him is how many different things he's doing all at once. "I said, 'Just choose one: solar or cars or rockets,'" Elon's mother Maye Musk told Time. "Obviously, he didn't listen."

Limited time on Earth?

Why is Musk so driven to do so much so fast, to the point that he didn't celebrate his 47th birthday and just barely attended his brother's wedding? The answer seems to be because he feels mortal and doesn't want to waste a moment of the limited resource that is a human life. "After a severe bout of malaria nearly killed him in 2001, those close to him say, he seemed to feel an urgency to make more of his time on Earth," Time reported.

"Time on Earth" may be a poor choice of words when it comes to Musk, who plans to spend some of his life on Mars. But the sense of urgency is certainly there. Mars Society founder Robert Zubrin, who's been friends with Musk for 20 years, told Time that this feeling of mortality is behind Musk's stunning accomplishments. "Genius is a word that is frequently associated with Musk; wisdom is not," he said. "But there is one sense in which Musk, in my view, is very wise, which is that he understands that he doesn't have forever."

That comment made me think of another iconic genius entrepreneur who also ran more than one company at at time--Steve Jobs. Even before he was diagnosed with the pancreatic cancer that eventually killed him, those who knew Jobs said he lived his life with an apparent sense of urgency, seeming to know by instinct that it would not be a long one.

 Jobs talked about this sense of mortality in his iconic 2005 Stanford commencement speech. "Remembering that I'll be dead soon is the most important tool I've ever encountered to help me make the big choices in life," he said. "Because almost everything--all external expectations, all pride, all fear of embarrassment or failure--these things just fall away in the face of death, leaving only what is truly important. Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart."

There's a growing audience of Inc.com readers who receive a daily text from me with a self-care or motivational micro-challenge or idea. Often they text me back and we wind up in a conversation. (Interested in joining? You can learn more here.) Some, who have suffered the loss of a close loved one or life-threatening illnesses themselves text me that they learned this same lesson the hard way. You have one life, make every moment of it count.

Jobs and Musk are right, and so is my text audience. None of us truly knows how much time we have to live, whichever planet we're living on. It may be less than we think; it will almost certainly be be less than we wish. Whatever is most important to us--family, romance, friendship, starting a company, building electric cars, flying rockets to Mars, or creating the world's first truly smart smartphone--tomorrow isn't good enough. We had better get to it today.