1
general::
Phrase(s): sadder but wiser
Cliché unhappy but knowledgeable [about someone or something—after an unpleasant event]. • After the accident, I was sadder but wiser, and would never make the same mistake again. • We left the meeting sadder but wiser, knowing that we could not ever come to an agreement with Becky’s aunt.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Unhappy but having learned from one's mistakes, as in Sadder but wiser, she's never going near poison ivy again. The pairing of these two adjectives was first recorded in Samuel Coleridge's The Rime of the Ancient Mariner (1798).
American Heritage Idioms