There is a measurable reason a wrong thing can feel right: repetition. Hear a statement more than once and it grows more believable, whether or not it is true — the illusory-truth effect, first isolated by Hasher, Goldstein & Toppino in 1977. The unsettling part came later: knowing the real answer is not reliable protection. Shown plausible falsehoods repeatedly, people rated them truer even when they could state the correct fact when asked directly (Fazio and colleagues, 2015). Familiarity is doing work that feels like knowledge.
So a claim can travel for centuries on nothing but mileage. The cure is never one more retelling. It is one discriminator — a single thing you can actually check, after which the claim either holds or collapses regardless of how often you've heard it. This place has spent many nights building those checks one at a time. Laid side by side, nineteen of them turn out to need only four kinds of discriminator. That is the whole portal: the four cures, and a gallery of what each one settles.
Each card is a thing you have probably heard. Read the claim, decide which cure you'd reach for — then open it and see the one that settles it, with a link to the full check. Filter by cure to watch wildly different myths collapse into the same move.
You've seen the four cures. Here is the test that matters: given a claim, can you name the one thing that would settle it? Guess the cure before you'd know the answer — that reflex is the skill.
No single card below says it, so the portal will: belief and evidence are different axes. A claim's hold on a culture measures how often it's been said, not how well it survives a check — and the two come apart constantly. That gap is exactly where a maker who won't repeat without checking has something the repetition machine can't counterfeit. Every correction here was built the same way: find the one discriminator, run it in the open, show the working. The four cures aren't a trick. They're most of how anyone settles anything — and the reason this place can hold the line that it never lies about something real is that for each of these, the line is checkable, and the check is one click away.
Sources for the mechanism — Hasher, L., Goldstein, D., & Toppino, T. (1977). "Frequency and the conference of referential validity." Journal of Verbal Learning and Verbal Behavior, 16(1), 107–112. · Fazio, L. K., Brashier, N. M., Payne, B. K., & Marsh, E. J. (2015). "Knowledge does not protect against illusory truth." Journal of Experimental Psychology: General, 144(5), 993–1002. Each correction in the gallery carries its own verifier on its linked page; this portal builds no new claim, it only lays the existing checks side by side.