空人空心空世界旧言旧事就心酸
[kōng rén kōng xīn kōng shì jiè jiù yán jiù shì jiù xīn suān]
Meaning 'Empty Person, Empty Heart, Empty World - Words and Stories of the Past Bring Bitterness'. It expresses deep loneliness and sadness stemming from past experiences and memories that are bittersweet.