往事旧年换一句好久不见
[wăng shì jiù nián huàn yī jù hăo jiŭ bù jiàn]
The memories of bygone years exchanged for a casual 'long time no see' - reflecting reminiscence about old times replaced merely by a short greeting when encountering acquaintances again after a separation. It expresses bittersweet sentiments toward the past changing into polite formalities now.