旧人旧梦旧成伤旧人旧梦旧时光
[jiù rén jiù mèng jiù chéng shāng jiù rén jiù mèng jiù shí guāng]
'Old lovers, old dreams and the hurts in bygone times'. It implies nostalgia for past relationships, reminiscences, and bittersweet emotions related to those past events that left lasting impacts and memories.