杞人忧天qǐrén-yōutiān

《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

英like the man of Qi who was haunted by the fear that the sky might fall

比喻不必要的忧虑

英with unwarranted anxiety