年华若流逝物是人非即汝如付时光白首不相离
[nián huá ruò liú shì wù shì rén fēi jí rŭ rú fù shí guāng bái shŏu bù xiāng lí]
Expresses profound sadness about changes in people over time while longing for an eternal relationship: If things were always the same even as time flows, we would grow old without parting.