Elon Musk says Jeff Bezos takes himself 'a bit too seriously'

• Elon Musk said Jeff Bezos takes himself too seriously in an interview with the Financial Times.
• Musk is known for constantly tweeting and sharing memes.

Jeff Bezos needs to cut loose, according to Elon Musk.

The Tesla and SpaceX CEO said his fellow billionaire "does take himself a bit too seriously," in an interview with the Financial Times published Wednesday naming him its Person of the Year. Musk and Bezos, the two richest people on the planet, have feuded for going on two decades.

Musk may lead the most valuable carmaker on the planet — and one of the most valuable public companies, period — but he doesn't act like it. At least not in the traditional sense. Unlike top executives as other firms, Musk regularly tweets out memes, juvenile jokes, and the occasional company update to his 66.5 million followers. He frequently engages with fans online and gets into spats with critics.

"I keep forgetting you're still alive," Musk recently replied to a tweet from Sen. Bernie Sanders calling for higher taxes on the wealthy.

Bezos' public image, by comparison, is highly curated. He has only 3 million followers on Twitter and isn't prone to the same unfiltered musings and casual banter as Musk. That may not be such a bad thing, as Musk's tweets have landed him in hot water with the US Securities and Exchange Commission. One notorious comment about taking Tesla private led to a $40 million settlement that also required lawyers to review some of Musk's future social media posts.

Musk's comments are just the latest in a 15-year feud between the two centibillionaires, which has intensified amid a growing rivalry between their rocket companies, SpaceX and Blue Origin. "Turns out Besos [sic] retired in order to pursue a full-time job filing lawsuits against SpaceX," Musk tweeted in August. Bezos stepped down as Amazon CEO in July.

In the same breath as he criticized Bezos for being too serious, Musk said his rival doesn't work hard enough on his space company, Blue Origin.

"In some ways, I'm trying to goad him into spending more time at Blue Origin so they make more progress," Musk told the FT. "As a friend of mine says, he should spend more time at Blue Origin and less time in the hot tub."