Every option weighed costs energy; every option held open costs more. On a heavy brain-fog day, 'what do you want for dinner?' is not one question — it is a search through possibilities, a cost-check against how today went, and a prediction of how the evening will land, all before anything is cooked.

Decision fatigue works the same way for everyone — the difference is the budget. Where someone else spends a coin of attention on a choice, you may be spending a note. That is not indecisiveness; it is the honest exchange rate of a low-capacity day.

Slow processing adds to it: thoughts that used to arrive instantly now queue. Being asked to decide quickly can cost more than the thing being decided about — which is why being allowed to say 'I'll come back to you' is such an important accommodation.

The fastest way to make deciding cheaper is to shrink the menu. Twenty options guarantee a long, costly search; two options guarantee a short one. The two-option rule is simply that: give yourself two, pick one, and let 'good enough' be the standard.

The rule matters most when fog is heaviest — which is exactly when it is hardest to remember. So it works best as a written card kept where decisions happen: on the phone, on the fridge, in the notes app that is already open.

Others can be invited into the rule too: 'send me two times that suit you and I'll pick one' turns an open-ended negotiation into a single choice.

Not all decisions deserve equal care. A reversible decision — what to watch, what to eat, whether to go out today — can be made quickly and cheaply, because it can be changed later for less than it costs to deliberate now.

Harder-to-reverse decisions — financial commitments, medical choices, things affecting other people — deserve the opposite treatment: time, information, and often another person's input. Sorting a decision into its class before deciding anything is often the most useful second of thinking in the day.

Sorting wrongly in the direction of over-deliberation is the common failure: spending hard-decision effort on soft decisions. If it can be undone tomorrow, decide it in ten seconds.

A default is a decision made in advance, on a clearer day, that removes the same decision from every future day. The rotating five-meal plan. The standard reply to invitations. The default rest time. The 'if it's before 10am, I don't answer the phone' rule.

Defaults are strongest when written down. On hard days you follow them instead of re-choosing them — and following a default you set yourself on a good day is autonomy, not rigidity. They can be changed on any better day, by the same person who set them.

Households can run on shared defaults too: everyone knows what happens on a bad day (the default meal, the default script, the default answer), which removes the negotiation as well as the decision.

Every incoming decision has three honest destinations: decide now (if it is small, or time-critical), decide later (with a stated time, which closes the loop without closing the thinking), or not at all (some questions deserve to be dropped entirely rather than carried).

The fourth destination is 'not me': some decisions can be delegated outright — to a partner, a friend, a paid service — because the outcome matters less than the capacity. 'You choose, I trust you' is a complete sentence and a real skill.

The failure mode is leaving decisions in none of these states — undecided, unassigned and unstated, so they run as background load all week (see Capacity & Demand on open loops). A decision parked with a date costs nothing; a decision left floating costs every day it floats.

It is possible to gather more information than a decision needs — and with ME/CFS, gathering is often the most expensive part. The information minimum is the smallest amount that makes a good-enough decision possible, and deciding to stop there is legitimate.

Perfect information does not exist for most ordinary choices, and waiting for it is usually a decision by default. 'Deciding with incomplete information' is the normal human condition; the only question is whether the incompleteness is acceptable for the stakes — which the reversible / harder-to-reverse sort already answers.

A practical form: write down what would actually change the decision if you knew it. If the honest answer is 'nothing', you already have enough.

A conditional decision is a default with a fork in it, made in advance when thinking is cheap: 'if I sleep badly, I'll take the taxi; if I sleep okay, I'll walk part of the way.' It removes tomorrow's weighing by deciding the rule instead of the outcome.

Conditionals work well for social plans ('if I'm having a difficult morning, I'll come for the last hour only') and for medical days ('if the appointment runs long, I'll skip the shop on the way home'). One sentence, written on a clearer day, saves a morning of negotiation with yourself.

And whatever kind of decision it is, one at a time is not a limitation but a method: a queue of open decisions is a demand stack (see Capacity & Demand), and closing one thing fully costs less than inching three things forward.

Sorting by stakes happens before any deciding: low-stakes choices (food, which jumper, what to watch) get seconds; high-stakes choices (money, health, commitments) get time, information and usually another voice. Most of the day's decisions are low-stakes, and treating them that way returns a surprising amount of capacity.

Decisions under pressure — a form on the counter, a professional pushing for an answer in an appointment — have a script: 'I don't decide things like this on the spot. I'll come back to you.' It is a complete answer, and a boundary (see Communication & Boundaries for handling pushback).

Finally: changing your mind is a legitimate outcome, not a failure of the original decision. New information, a change in capacity, or simply learning that the choice was wrong are all honest reasons. Reversible decisions exist partly so that changing your mind is cheap.