"who would have thunk it : (colloquial, sometimes sarcastic) A rhetorical question used to express..."

“who would have thunk it : (colloquial, sometimes sarcastic) A rhetorical question used to express incredulity: who would have guessed it?; who would have thought that would happen?”

- https://en.wiktionary.org/wiki/who_would_have_thunk_it#English

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