Long before he became the first person in history to reach a trillion-dollar net worth, Elon Musk was sleeping on an office couch and showering at the YMCA to keep his first company alive.

The video clip which has resurfaced recently comes from a speech delivered back in 2014 at the Marshall School of Business at USC, where the now 55-year-old explains precisely the practices that led him to his current position atop the global wealth league tables.

How did a 100-hour workweek shape Elon Musk's early career?

In the video, Musk describes building Zip2, the online city-guide software company he........

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