huí / xiǎng / qǐ / nà / duàn / shī / bài / de / jīng / lì / ， / tā / bù / jīn / kǎi / tàn / rén / shēng / wú / cháng / 。

回想起那段失败的经历，他不禁慨叹人生无常。

Thinking back on that failed experience, he could not help lamenting the unpredictability of life.