there was a man in the State of Wei called Geng Lei.
戰國時期(公元前403―221年中國中原地區各諸侯國連年爭戰的時代)魏國有個名叫更羸的人。
One day he said to the king: ‘I can shoot down birds by simply plucking my bowstring.’
壹天，他對國王說：“我只要拉開弓，空射壹下，就能把天上的鳥射下來。”
When the king expressed doubt
Geng Lei pointed his bow at a wild goose flying in the sky
anged the bowstring
and the goose fell to the ground.
國王不相信。更羸便對準天上飛來的壹只雁射去，果真那只雁聽到拉弦的聲音就掉了下來。
The king thought it was strange
Geng Lei said
‘This goose has been hurt in the past. Hearing the ang of the bowstring
it assumed that it was doomed. So it simply gave up trying to live.’
國王感到很奇怪。更羸說，“那是壹只受過傷的雁。它壹聽到我拉開弓弦的聲響，就驚慌得支持不住，自然要掉下來了。”
This idiom means that if one has been frightened in the past one's will may bee paralysed in a similar situation.
“驚弓之鳥”這個成語比喻受過驚恐之後，有壹點動靜就特別害怕。