Level 0 - Search: Query → Results (Quadfecta) Level 1 - RAG: Query → Retrieve → Generate (exists) Level 2 - Agentic RAG: Agent decides when/what to retrieve (partial) Level 3 - Cognitive Memory: Auto-recall, linking, reasoning over memory (THE GOAL)
Level 3 is what makes AI 'remember' - not storing everything in parameters, but having triggers that surface relevant knowledge automatically.