Why LLMs Have No Memory — A Cross-Validated Research Report with 67 Primary Sources
TL;DR # “LLMs have no memory” isn’t an oversight — it’s the equilibrium of four compounding constraints: O(n²) attention + KV cache VRAM + catastrophic forgetting + GDPR compliance. Every “Memory” feature from ChatGPT / Claude / Cursor works the same way: inject structured text back into the system prompt. Weights never change. Prompt Caching is performance optimization, not memory. The mainstream for the next 1–3 years is “stateless LLM core + stateful Agent memory layer”.