机会难得,不可错失。《旧唐书・卷六十七・李靖传》:“兵贵神速,机不可失。”《宋史・卷三六四・韩世忠传》:“金人废刘豫,中原震动,世忠谓机不可失,请全师北讨,招纳归附,为恢复计。”
英语 Don't let slip an opportunity(A golden opportunity is not to be missed; Now or never!; Occasion knoks but once)
拉丁语 Nunc aut nunquam.