Why decluttering wears you out faster than the mess itself
You did not run out of energy. You ran out of decisions. Sorting is not physical work — lifting a box of old cables costs almost nothing — but deciding whether to keep each one is a real cognitive act, and the quality of those decisions degrades the more of them you make in a row. By the third hour you are either keeping everything out of sheer fatigue, or throwing away things you will miss. Neither is a character failure. It is what decision fatigue looks like from the inside.
What is actually running low
Willpower and judgment draw from the same limited pool across a session, and that pool does not care whether the decisions are big or small. Deciding whether to keep a chipped mug spends roughly the same reserve as deciding whether to keep a wedding gift you never liked. String enough small ones together and you arrive at the hard ones already depleted, which is exactly backwards from what you need. This is also why decluttering advice that works beautifully for the first hour — "just ask yourself if you love it" — stops working by the second. The question has not changed. Your capacity to answer it honestly has.
Why it hits decluttering harder than almost any other chore
Laundry does not ask you to decide anything; you already decided to keep every item in the pile. Decluttering is nothing but deciding, item after item, and — unlike sorting mail into two obvious bins — very few objects are alike enough to reuse the same judgment. A drawer of screws lets you make one rule and apply it fifty times. A shelf of gifts, souvenirs, and half-used hobby supplies asks for fifty separate, unrelated judgments, each pulling on the same tired reserve. That is why an afternoon in the garage can leave you more drained than a full day at a desk: the garage is denser with unrelated decisions per square metre than almost anywhere else in the house.
Order the work so you spend the budget on purpose
Group by category, not by room, and go from the lowest-friction category to the highest. Cables, expired pantry items, and carrier bags let you set one rule and apply it many times without re-deciding — that is cheap, and it should come first while your reserve is full. Save anything that needs individual judgment — clothes that almost fit, gifts, tools you meant to learn to use — for a separate, shorter session, ideally a different day, so it gets decided with a full reserve instead of the leftovers of one. Doing the hard category last in a long session is the single most common way a good day of progress ends in a pile abandoned on the floor.
The "maybe" pile is fatigue management, not indecision
Forcing a final answer on every object when your reserve is empty produces bad answers in both directions — reflexive keeping, or a decision you will regret and quietly re-buy later. A bounded "maybe" box, dated and revisited in a few months, is not a cop-out. It is the correct move when the honest answer is "I cannot tell right now," and it costs almost nothing because most of what goes in never gets missed by the time you open it again.
Where remembering less actually helps
A surprising share of decision fatigue during a declutter comes from re-deriving facts you already knew once — how many of these you own, whether you have touched it this year — from memory, on the spot, under pressure. That is expensive precisely because it is not a values question, it is a lookup, and lookups should not cost willpower. This is one of the quieter reasons Kept keeps a last-used date on anything you log: "412 days" answers the question instantly and without an argument, where "I think it's been a while" invites one. It will not make the sentimental decisions for you — nothing should — but it removes the ones that were never really decisions to begin with, and saves the reserve for the ones that are.
What pacing it right looks like
Not a single heroic weekend. Short sessions, stopped while you still have judgment left rather than pushed until you are making bad calls just to be done, with the hardest category scheduled for when you are freshest, not when you are already tired of the whole thing. The goal is not to prove you can push through. It is to spend a limited resource on the decisions that are actually worth making with it.