Crypto fan-turned-hater Nassim Nicholas Taleb wants you to know that Bitcoin is a “tumor.”

In an interview with CNBC’s Squawk Box Thursday, the author of The Black Swan argued that anyone under 40—Millennials and GenZ—don’t understand how the economy works because of the Federal interest rate environment in which they’ve grown up.

“I think that we’ve had 15 years—14 and a half years—of Disneyland that basically has destroyed the economic structure,” Taleb said. “Think about it—no interest rates. So anyone who’s say 40 years old […] has no experience in markets. Zero. They don’t know what the time value of money is.”

Taleb’s bestselling book, The Black Swan, explores luck, risk, uncertainty, and probability. It’s based on the concept of a “black swan event,” which is unpredictable, has massive impact, and is rationalized after the fact to be less random and more predictable.

In his Thursday interview, Taleb argued that the U.S. Federal government lowered interest rates far too much, and eventually society will have to face the consequences.

“Zero interest rate for a long period of time, you are hurting the economy, you are creating bubbles, creating tumors like Bitcoin,” Taleb said. 

Just a few years ago, Taleb was into cryptocurrencies and owned some himself. Back in April 2020, he told Lebanese people to “use cryptocurrencies!” to get around the country’s financial system.

A few months later, he complained about Coinbase’s customer support on Twitter and then closed his Coinbase account.

By February 2021, Taleb declared Bitcoin “a failure” because of its volatility and said he was selling his Bitcoin. In April last year, he continued his downward spiral into no-coinerdom, claiming Bitcoin “has characteristics of an open Ponzi.” 

While Taleb is now urging society to “go back to normal economic life,” he also argued that “we’re still far away from stressors.”

“Bitcoin is still used, it’s still at $20,000. It’s not at, you know, at $1,000 or zero.”