# Knowing What You Don’t Know > Source: > Published: 2026-06-04 17:57:29+00:00 Why the next real breakthrough in AI isn’t a bigger brain — it’s a machine that can admit ignorance. A reader caught me out. Last column I argued that the great AI buildout — the hundreds of billions pouring into data centers and the GPUs that fill them — is aimed at the wrong layer. We are spending as if the bottleneck were the size of the model’s brain, when the real bottleneck is getting the right information in front of it. Cheap retrieval, I said, not expensive cognition. A reader replied, pointing out the name Jevons. In 1865, a young English economist named William Stanley Jevons noticed something strange about coal. As steam engines got more efficient — as they wrung more work out […] The post