hit the nail on the head字面意思是“一下子钉准到图钉钉帽”，引申为“击中要害；说到点子上；一针见血”。

【例句】
Mike hit the nail on the head in his speech on the demerits of the existing housing policy.
迈克在演讲中一针见血地指出了当前房屋政策的弊端。

You really hit the nail on the head when you said there's no point training people for jobs that don't exist.
你说为不存在的工作进行人员培训是没用的，这话真是击中了要害。