in the spring and autumn period, duke1 huan of qi led an army to attack a small state in the north. they went in spring when green grass covered the ground. but when they came back it was winter. *rywhere was white with snow and the wind was how*ng. the troops2 lost their way. while *rybody was worrying, guan zhong, the duke's chief minister, suggested:"an old horse may know the way." so the duke ordered s*ral old horses to be selected to lead the army. finally, they found the way back home.
this idiom refers to the value of experience.
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