一聚未到白首一别已是经年
[yī jù wèi dào bái shŏu yī bié yĭ shì jīng nián]
Met briefly before reaching old age together, parted ways and years have passed since then. This conveys the sadness of brief encounters with little reunion, followed by long separations across many years, possibly reflecting on a love affair or friendship that never fulfilled expectations or desires.