grasp the nettle

该用法来自谚语: Grasp the nettle and it won't sting you. (大胆抓荆棘,荆棘不刺手。你不怕困难,困难就怕你。)如果轻碰荨麻很刺手，但是紧握反而不刺手。于是grasp the nettle就表示"迎难而上; 知难而进; 大胆抓棘手问题"。

to force yourself to be brave and do something that is difficult or unpleasant

迫使自己迎难而上;果断处理棘手的问题;破釜沉舟

You've been putting off making that phone call for days - I think it's about time you grasped the nettle!

那个电话你拖了好几天都没有打—— 我觉得你应该果敢地去面对这个问题。