当灯火通明时看到的全都是你
[dāng dēng huŏ tōng míng shí kàn dào de quán dōu shì nĭ]
Meaning 'when all lights are shining bright, everything I see is you.' It describes a state of heightened awareness or obsessive thoughts wherein even amidst well-lit places meant for social interaction or lively activities, the person can only think about one beloved or admired figure.