A person who reads only agreement eventually mistakes repetition for proof.

Hearing the same claim from many sources feels like corroboration, and if the sources all share an origin, it is only repetition. This is how confident and mistaken positions get built: not through poor reasoning but through a sample that was never independent.

When something seems widely established, check whether the accounts are actually separate or all tracing back to one place. Ask where each source got it. This is a small habit and it protects you against a surprising number of errors, particularly the ones everyone around you shares.