得魚忘筌（得魚忘筌）　

◎ 得魚忘筌 déyú-wàngquán

[forget the means by which the end is attained;forget the trap as soon as the fish is caught] 筌是用來捕魚的器具。得到了魚,就忘掉筌。比喻達(dá)到目的以后就忘了賴以成功的東西

筌者所以在魚,得魚而忘筌。——《莊子·外物》