Something of the reasoning behind this conjecture is revealed in a joke which is currently going the rounds among taxi drivers: a cabby gets into an argument, and blazing with anger, jumps out of his cab to give the other fellow a thrashing. But when he gets out he finds his legs have turned to jelly, and he can hardly even stand, let alone fight.
據說有位計程車司機與人發生衝突，他怒氣沖沖地下車預備揍人，結果下了車發現自己像個「軟腳蝦」，連站都站不穩，更遑論出手打人了。