The unfalsifiable claim that the world was created recently, complete with fabricated memories, aged rocks, and light already in transit from stars that never shone.
Documented
Omphalos, the navel problem, 1857
Documented: Gosse's Omphalos argued that a created world must bear the marks of a history it never had, the navel Adam never needed. He was honest that this makes the fossil record divine set dressing, and the book was savaged from both sides, by scientists for being unfalsifiable and by clergy for making God a forger. Russell's Analysis of Mind (1921) gave the idea its modern form: there is no logical impossibility in the world springing into being five minutes ago, memories included.
Assessment: Documented as a serious philosophical puzzle wearing a joke's clothes. It is the cleanest demonstration that the past is an inference, not an observation, and it sits in the direct lineage of our Phantom Time, New Chronology, and simulation files.
Stories
The Church of Last Thursday
The folk version became scripture-by-parody: online communities in the 2000s founded Last Thursdayism as a mock faith, complete with schisms, heretics who believed in Last Wednesdayism, and a doctrine that the universe was created last Thursday and will be uncreated next Thursday. Like the Flying Spaghetti Monster, the joke is the argument.
Assessment: Documented internet folklore. The parody works because the position is genuinely unanswerable: every refutation is itself part of the fabricated record. The mock church simply refuses to pretend otherwise.
Interesting claims
The bootstrap cousin
The interesting claim is the family resemblance the file exposes: Last Thursdayism is Boltzmann Brains wearing a calendar, the simulation argument wearing a bishop's collar, and the bootstrap paradox applied to history itself. Four separate shelves of this archive keep rediscovering the same vertigo: a record is not a guarantee.
Assessment: As metaphysics it is permanent and unkillable, which is exactly its diagnostic value. As history it is empty: the hypothesis predicts everything and therefore nothing. File it as the terminal point every chronology skeptic arrives at if they refuse to stop doubting.
Sources and further reading
Gosse, Omphalos: An Attempt to Untie the Geological Knot (1857), the original claim
Russell, The Analysis of Mind (1921), the five-minute world
The Last Thursdayist communities of the 2000s web, the parody church
Gardner, Fads and Fallacies (1952), on why unfalsifiability is not a virtue
Worth asking
Everything you call evidence is consistent with a world built last Thursday. What, exactly, are you standing on?