Welcome back to Second Thought, where we think about the zeitgeist, then think about it some more. This week, three 22-year-olds became the youngest billionaires in history. How? Artificial intelligence, of course. Where? Obviously, San Francisco—where I recently spent a few days hanging out with the young founders and builders trying to cash in on the AI boom.

Down the block from Elon Musk’s old house, about 10 minutes from San Francisco International Airport, there’s an 18,000-square-foot mansion with a pool, a bocce court, and a koi pond that absolutely no one is enjoying. That’s because the property—which is sprawling, lush, and gated—is the home to 10 or so young men and women who rarely step outside, because their worlds are on their monitors.

They call the place AGI House—as in, artificial general intelligence, a hypothetical point where machines can outdo humans in all mental tasks—and here, wannabe tech titans sweat over their ideas for companies, attend networking events, sit through research summits on agenticism, and decline alcohol at happy hours—they’re there to discuss cybersecurity.

Essentially, it’s the Playboy Mansion for nerds.

The house is rented by Rocky Yu, a local real estate agent who runs AGI House. Jeremy Nixon, who has since splintered off to start another AGI House, was an early resident there. He and Yu are currently in a legal battle over who came up with the name. But that’s by the by. Today, standing in a grand dining room that’s been refigured with rows of cheap tables and dozens of chairs, Josh Payne, one of the original residents, tells me that AGI House is dipping its toe into incubation.

For the hundredth time since I had arrived in San Francisco just three hours before, I had to ask: What does that mean?