我本薄荷为何心凉我非柠檬为何心酸
[wŏ bĕn bó hé wéi hé xīn liáng wŏ fēi níng méng wéi hé xīn suān]
Literally it goes 'I am mint, why is my heart cold? I am not lemon, why do I feel bitter?' It uses metaphors of taste sensations (coolness associated with mint, acidity with lemons) to express inexplicable emotional conditions—feeling cold-hearted or embittered against oneself.