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general::
Phrase(s): It is a poor heart that never rejoices. [and] It is a sad heart that never rejoices.
Prov. Even a habitually sad person cannot be sad all the time. (Sometimes used to indicate that a habitually sad person is happy about something.) • Jill: I’ve never seen Sam smile before, but today, at his retirement party, he smiled. Jane: It is a poor heart that never rejoices.
McGrawhill's American Idioms And Phrasal Verbs