How it works
A product offers a genuine setting — a sort order, a quality level, a notification preference, an autoplay switch, a tracking opt-out. The customer changes it and the product complies immediately and completely. Nothing is broken and nothing is refused.
Then the session ends, the app restarts, an update ships, or a period of inactivity passes, and the setting quietly returns to the company's preferred state. The burden of maintaining the customer's own stated preference is transferred, permanently, to the customer.
CHI applies an additional condition before recording this pattern: the forgotten preference must systematically benefit the company or advance the company's preferred behavior. A setting that fails to persist in both directions is a defect. A setting that only fails in the direction that costs the company revenue, engagement or data is a pattern.
Recognition checklist
What to look for
The setting works, once
The change is honoured immediately, so the customer has no reason to believe anything is wrong — which is what distinguishes this from a refused or hidden option.
It reverts without notice
The customer is not told the preference has lapsed. They discover it by noticing the old behavior has returned, often several sessions later.
It only forgets in one direction
The reset consistently restores the configuration that serves the company. The customer's preference is the only one treated as temporary.
Where it appears
Associated companies
Established by the Facebook investigation, which found that from approximately 2009 to 2026 customers could reach chronological and friends-first views of their feed but could never make one the view the product opens in. The pattern is newly adopted and additional companies are recorded as assessments test for it. The Instagram investigation corroborated it in stronger form: a Following feed that resets to algorithmic Home every session, a recommendations snooze that expires after 30 days by design, and a political-content preference changed in both directions without the customer asking.
Important distinction
Not a default, not an illusion, not a bug.
Default selection concerns where a customer starts. Choice Illusion concerns options that were never meaningfully real. Algorithmic Replacement concerns what a feed became. Preference Amnesia is none of these: the option is real, the customer successfully used it, and the product declined to remember.
Genuine technical defects also exist, and they are not this pattern. The test is direction: bugs forget in both directions, and this does not.