in the three kingdoms period (220-280), the king of the wei, * rui, wanted to select a very capable man to work for him. he said to his ministers: 'when choosing a talented person, always beware1 of（小心，谨防） one with a false reputation. a false reputation is just like a picture of a cake; it can' t reli*（解除，减轻） hunger.'
later, this idiom came to be used to mean comforting oneself with unrealistic（不切实际的） thoughts, without solving practical problems.
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