旧城旧梦旧人心半真半假半幻想
[jiù chéng jiù mèng jiù rén xīn bàn zhēn bàn jiă bàn huàn xiăng]
With meanings close to 'old city, old dream, and half true, half imagined old heart,' it implies lingering sentiments and nostalgia about people, places, and times from the past, with an uncertain blend between what really happened and what might've been fantasy.