What is Knuth root of all evil?

Knuth root of all evil is a concept in personal epistemology: Optimizing before you understand the system is the root of much wasted effort.

Example: You spend three weeks building a caching layer for your personal knowledge review system because you assume retrieval speed will matter at scale. Six months later, you still have 200 notes and the bottleneck is actually that you never review them at all. The optimization was technically sound. It was also completely irrelevant to the actual constraint — which was a habit problem, not a latency problem. You optimized the wrong layer of the system because you never measured which layer was failing.

This concept is part of Phase 29 (Agent Optimization) in the How to Think curriculum, which builds the epistemic infrastructure for agent optimization.