'Done a Lot of Difficult and Significant Things': Elon Musk Says These Current and Former CEOs Are the 'Smartest' The once icy relationship between Elon Musk and Jeff Bezos has appeared to thaw.

"I think in 10 years, based on the current rate of improvement, AI will be smarter than the smartest human," Musk said.

Related: How Do Billionaires Become Best Friends? They Launch Rockets on the Same Day. That's What Elon Musk and Jeff Bezos Did.

But when Cruz asked Musk who the smartest CEOs are, his answer was almost more surprising, considering some of his past drama.

Musk once again praised his one-time rival, Amazon founder Jeff Bezos, saying that smart people take action.

"To some degree, smart is as smart does," Musk said. "What have they done that is difficult and significant? You know, Jeff Bezos has done a lot of difficult and significant things."

Bezos and Musk have been fighting (and most of it publicly on social media) for decades over everything from poaching employees to space contracts.

Musk also named Google co-founder Larry Page to the smart-CEO list and said Oracle co-founder Larry Ellison is "one of the smartest people" he knows.

Page co-founded Google with Sergey Brin in 1998 and served as CEO until 2001. He then returned as CEO of the now-parent company, Alphabet, from 2015 until 2019. Ellison founded Oracle in 1977 and served as CEO until 2014. He is still the company's Chief Technology Officer.

Elon Musk is the richest person in the world, with a net worth of $312 billion, according to Bloomberg. And everyone he mentioned on the podcast as brilliant isn't too far behind.

Bezos is ranked No. 2 with $217 billion, Ellison is No. 5 with $174 billion, and Page is No. 8 with $149 billion.