- 时不再来 shíbùzàilái opportunity knocks but onceTime or opportunity once lost will never come back again; often used to encourage someone to seize the moment, and frequently paired with [[机不可失|機不可失|ji1 bu4 ke3 shi1]].
- 机不可失，失不再来 jībùkěshīshībùzàilái opportunity knocks but onceOpportunity knocks but once; do not let the chance slip by because it will not come again.
- 机不可失，时不再来 jībùkěshīshíbùzàilái opportunity knocks but onceAn idiom meaning that one must seize an opportunity when it arises, as it will not come again
- 青春不再 qīngchūnbùzài one's youth will never returnOne will never be young again; used to emphasize making the most of one's opportunities while young.
