Water under the bridge
Meaning
Past events that are forgiven or no longer important.
Usage
Common in reconciliations and conversations about moving on.
Origin & History
Origins and dates here are approximate summaries. Many idioms have disputed or unknown origins, and not every date has been checked against a historical dictionary, so treat specific dates and stories as a starting point rather than a citation.
Imagery of water flowing away to signify events that cannot be retrieved.
Appears in 19th-century writing describing past misfortunes being left behind.