失忆了笑着问你是谁转过身心痛了陌生人
[shī yì le xiào zhe wèn nĭ shì shéi zhuăn guò shēn xīn tòng le mò shēng rén]
It translates as 'I forgot and laughed while asking who you are; then turned around and got heartbroken by a stranger'. It conveys a somewhat melancholic mood - losing memories about someone important but meeting this person again as if strangers after a period. And even forgetting cannot ease the pain.