the.com/mists of time

The polite fog historians wave at facts they can't actually prove.

means A hazy, poetic way of saying nobody really knows the origin or exact details because it happened so long ago that the record has blurred.

from Built from ordinary English words, but the phrase hardened into a set idiom through centuries of poetic and historical writing, where 'mist' stood in for obscurity and forgetting — time pictured as a landscape receding into fog. It echoes older poetic habit (think Ossian-style 18th-century verse, fond of ancient things wreathed in mist) rather than tracing to any single coiner; by the 19th century it was already a comfortable cliché for 'too far back to verify.'

origin
Victorian poetic cliche, not ancient at all
function
makes forgetting sound majestic instead of lazy
usage tell
always precedes an unverifiable origin story
synonym
basically academic shrug with better PR
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