我不知惶恐为何物直到你离
[wŏ bù zhī huáng kŏng wéi hé wù zhí dào nĭ lí]
'I didn't know what fear was until you left' conveys feelings of insecurity that were absent until a specific separation occurred. It shows a realization of vulnerability after experiencing loss. It reflects an emotional transformation from being fearless to deeply impacted by the absence of someone significant.