He did his best work when he wrote the entire engine alone. That's no longer possible. You can however plausibly invent AGI alone. He said that an AGI implement

He did his best work when he wrote the entire engine alone. That's no longer possible. You can however plausibly invent AGI alone. He said that an AGI implementation is likely simple (meaning not complex), and I agree. The difficulty is in the method not lines of code, so it's work that fits him.