Context: The informant was four years old at a preschool birthday party when she first heard this phrase, said to her by a friend’s mother after she asked for a different popsicle flavor.
Analysis: This rhyming phrase is typically said to children in response to expressions of dissatisfaction (I’ve heard it many times as well). It seems to encourage a philosophy of being grateful for what one has, and not to trouble others with your own disappointment.