What is deliberate practice replacing defaults?

Deliberate practice replacing defaults is a concept in personal epistemology: Every deliberate agent you create replaces an unconscious default.

Example: You notice you check your phone within 30 seconds of sitting down at your desk every morning. That's a default agent: trigger (sit down), condition (phone is present), action (open email or social media). You design a replacement: same trigger (sit down), same condition (phone is present), new action (open your task list and select today's first deep-work block). The slot was never empty. You're overwriting, not installing from scratch.

This concept is part of Phase 21 (Agent Fundamentals) in the How to Think curriculum, which builds the epistemic infrastructure for agent fundamentals.