遗憾是会呼吸的痛想念是会呼吸的痛
[yí hàn shì huì hū xī de tòng xiăng niàn shì huì hū xī de tòng]
A poetic way of expressing profound heartache and nostalgia, implying deep regret and longing so real it feels like they can 'breathe'. Both 'regret' and 'missing someone/something' become tangible aching entities.