What is decision fatigue energy?

Decision fatigue energy is a concept in personal epistemology: You can have time available but no energy to use it — energy management comes first.

Example: You blocked two hours for strategic planning — your top priority, assigned to your peak cognitive window, protected against meetings, exactly as Phase 35 taught you. The calendar is perfect. But last night you slept four hours because you stayed up anxious about a conversation you have been avoiding. This morning you ate nothing, drank three coffees, and spent twenty minutes doom-scrolling before you opened your laptop. Now you are sitting in front of the blank document during your protected block, and nothing happens. You read the same sentence three times. You write a heading, delete it, write another. After forty minutes you give up and open email, telling yourself you will try again tomorrow. The time was there. The energy was not. And time without energy is just a clock running while you stare at it.

This concept is part of Phase 36 (Energy Management) in the How to Think curriculum, which builds the epistemic infrastructure for energy management.