老骥伏枥

lǎojì-fúlì

[able men tied down to a routine post; ambition survives even in old age like the old steed in the stable that still wants to gallop a thousand li] 三国魏·曹操《步出夏门行》: "老骥伏枥, 志在千里。 烈士暮年, 壮心不已。 "(烈士: 有志功业的人)比喻年已老但雄心壮志不减当年