全世界都知道我爱你唯你不知道我爱你
[quán shì jiè dōu zhī dào wŏ ài nĭ wéi nĭ bù zhī dào wŏ ài nĭ]
It means 'Everyone knows I love you except you.' The user may imply unrequited feelings or a lack of recognition from someone they care for deeply, while everyone else is aware of their true sentiments. There's a sense of frustration and helplessness.