我孤陋寡闻不知你心有人
[wŏ gū lòu guă wén bù zhī nĭ xīn yŏu rén]
It translates to 'Ignorant as I am, I did not know you already have someone else in mind'. Here the user reflects feelings of naivete and disappointment from an unawareness or belated recognition of the fact they were liked or desired by someone else.