Let's 惊弓之鸟
被弓箭吓怕了的鸟。比喻受过惊吓的人，遇到类似的情况就很容易害怕。
A bird startled by the mere twang of a bow — someone so scarred by past fear that the smallest reminder sets them trembling.
战国时候，魏国有一位射箭高手，名叫更羸。他的箭法非常准，天下闻名。
有一天，更羸陪魏王在花园里散步。他抬头看见一只大雁从远处飞来，飞得很慢，叫声又很悲伤。更羸对魏王说：“大王，我不用箭，只拉一下弓，就能把这只大雁射下来。”
魏王不信。更羸拿起弓，用力一拉，“嘣”的一声。那只大雁一听见弦声，吓得使劲往高处飞。可它一用力，旧伤就裂开了，扑通一声，从天上掉了下来。
魏王很惊讶。更羸说：“这只雁飞得慢，是因为它身上有旧伤；叫得悲，是因为它离开了同伴。它一听到弓弦的响声，就吓得要命，所以自己掉下来了。”
从此，人们就用“惊弓之鸟”来形容那些受过惊吓、听到一点儿声音就害怕的人。
During the Warring States period, there was a master archer in the state of Wei named Geng Lei. His arrows never missed, and his name was known across the land.
One day, Geng Lei was walking with the King of Wei in the royal garden. He looked up and saw a wild goose flying slowly in the distance, crying a sad cry. Geng Lei said, “Your Majesty, I don't even need an arrow. Just the pull of my bow will bring that goose down.”
The king did not believe him. Geng Lei lifted his bow and pulled hard — twang! The goose heard the snap of the bowstring and, terrified, beat its wings to climb higher. But the effort reopened an old wound, and it tumbled down from the sky.
The king was amazed. Geng Lei explained, “It flew slowly because it carried an old injury. It cried sadly because it had lost its flock. The sound of my bowstring was all it took to frighten it to death — it fell on its own.”
Ever since, people use “a bird startled by a bow” to describe someone so haunted by past fear that the slightest sound makes them panic.