— web clipping, 3,510 words — published 2026-04-09
Geometry of Forgetting: Why Brains and LLMs Fail EXACTLY the Same Way
## TL;DR - Memory systems for LLMs forget EXACTLY like humans, reproducing the exact numbers from some of the most replicated experiments in clinical psychology. - For the last several months, we have been exploring a single observation: learned representations concentrate their variance in roughly 3 to 10% of their nominal dimensions. That concentration governs compression, attention, and, it turns […]
Summary by Claude Opus 5
Ashwin Gopinath's thread on spectral concentration: learned representations put their variance in 3–10% of nominal dimensions (KV cache keys at d_eff ≈ 4 of 128; three production embedding models all at ≈16 effective dimensions regardless of nominal size). The claim is that embedding spaces under noise and interference reproduce the quantitative signatures of human memory — power-law forgetting, false memories, tip-of-tongue, spacing effects — with no phenomenon-specific engineering.
Full text not reproduced here — kept as Geometry of Forgetting Why Brains and LLMs Fail EXACTLY the Same Way.md in Nathan's clippings archive.