☉ 杞人忧天 【qǐrényōutiān】
　　[ like the man of Qi who was haunted by the fear that the sky might fall ] 《列子·天瑞》:“杞国有人忧天地崩坠，身亡所寄，废寝食者”。传说杞国有个人怕天塌下来，愁得寝食不安。
　　[ with unwarranted anxiety ] 比喻不必要的忧虑。