Photo Illustration by Thomas Levinson/The Daily Beast/Getty Elon Musk, as a yet-unproven entrepreneur in his mid-twenties, declared himself the “reincarnation” of ancient Greek conqueror Alexander the Great, a new book on the billionaire has revealed. Musk, now 53, made the comment around 30 years ago to a partner at one of the firms that bankrolled his first start-up, Zip2, which aimed to bring the Yellow Pages online, Washington Post reporter Faiz Siddiqui writes in Hubris Maximus, published Tuesday. Derek Proudian, then at Mohr Davidow Ventures, recalled grabbing lunch with the young Musk to discuss how to make the company viable on a small scale.

Musk, however, insisted that he think bigger: Zip2 was “going to be the biggest company ever,” Proudian recalled him saying. When Proudian tried to change the subject, Musk doubled down. “No—you don’t understand," he said.

“I’m the reincarnation of the spirit of Alexander the Great.” Elon Musk, then an unproven start-up founder, declared himself the “reincarnation” of Alexander the Great. / Paul Harris / Getty Images Incredulous, Proudian pushed back that he might not reach that level of success. Musk wasn’t willing to hear it.

“I’ve got the samurai spirit,” he said. “I’d rather commit seppuku than fail.” In the 1990s, Proudian brushed off Musk’s words, saying that he didn’t “take it that seriously when he was a 23-year-old entrepreneur who didn’t have two nickels to rub together.” But with Musk now a multibillionaire who holds President Donald Trump’s ear (while still operating with the haughtiness of a young man who compared himself to one of history’s great conquerors), Proudian said he’s worried. “I am really concerned because I know how smart this guy is and I know how much money he has and I know how ruthless he is, and it’s playing out in front of my own eyes,” he said.

Musk now holds the president’s ear—but seems to bring a similar attitude to his work. / Andrew Harnik / Getty Images Musk did not immediately return a Daily Beast request for comment, sent to his lawyer, on the book’s claims. Siddiqui’s book charts the rise of the world’s richest man—from his relentless push to outdo competitors at Tesla to his chaotic takeover of Twitter—arriving at Musk’s current venture: making huge cuts to the federal government as the unelected chief of the Department of Government Efficiency.

True to its title, the book is ripe with fresh insider accounts of the arrogance of the “technoking”. Ross Gerber, a former Tesla investor and one of the company’s biggest cheerleaders, told Siddiqui that Musk cannot stand being told what to do—even by the Securities and Exchange Commission. “He just basically has a complete disdain for any authority period,” said Gerber, whose relationship with Musk eventually soured.

“I have a completely different opinion about the hubris of thumbing your nose at the people that could really hurt you.”