John Chambers knows bubbles. He steered Cisco Systems through the internet frenzy of the late 1990s, watching its market value soar to $576 billion in March 2000 before plunging 90% to $60 billion by late 2002. Today, at $340 billion, Cisco looks modest next to AI giants. But Chambers, now through his venture firm JC2 Ventures, spots echoes—and sharper edges—in the current AI surge. The Buffett Indicator, total U.S. stock market cap divided by GDP, sits at 232%. That’s past the dot-com peak. Far past Warren Buffett’s 200% “playing with fire” line from a 2001 Fortune piece. Chambers laid it out bluntly in a recent interview. “The driving force was the internet, and growth was almost completely out of control,” he told Fortune . Supply chains choked. Tech ruled valuations. Productivity jumped 50% annually. Sound familiar? AI promises the same transformation—work, life, learning, play. Bubbles ahead. Winners. Train wrecks. But differences glare.…