A customer support agent that forgets a user's billing conversation from two days ago isn't broken — it's just missing memory. Not persistence. Not idempotency. Memory . And they're not the same thing. That's the argument Ed Huang (CEO of PingCAP) makes in a sharp piece on The New Stack, and it's worth paying attention to. "Persistence without selection gives you a slow agent. Without compression, an expensive one. Without decay, a confidently wrong one. Without contamination prevention, an agent that gets dumber over time." What memory actually requires Most teams conflate three things with memory that aren't: Idempotency — prevents duplicate actions. Not memory. Workflow state — tracks where a multi-step process is. Not memory. Transactional consistency — prevents race conditions. Not memory. All necessary. None of them gives an agent a sense of history. Real agent memory has five layers: Persistence — history survives restarts. Most teams have this. Selection — deciding what's worth keeping. Most don't.…