老骥伏枥，志在千里(曹操《步出夏门行》)

An old steed in the stable still aspires to gallop a thousand miles—Old people still cherish high aspirations.(Cao Cao)
～；烈士暮年，壮心不已。An old horse in the stable still aspires to gallop a thousand miles;A hero in his late years does not give up his lofty aspirations.or:Yet ancient steeds in stall that lie,Dream of the leagues they ran;And heroes,though their doom is nigh,As ever play the man.or:A veteran thoroughbred in the stable still dreams of the wilds; A man of action,though advanced in years,aspires after great exploits.(Cao Cao)