wiser是指“聪明的人”，never the wiser永远也不是明白人，即“依旧不懂，一窍不通，仍然一无所知”。

【例句】
Tony proposed on their own timetable-on Valentine's Day-and her mother was never the wiser.
托尼按照他们自己的计划在情人节这天向她求婚了，而希瑟的妈妈仍然对女儿造假一无所知。

For all my advice she was never the wiser.
虽然我全力指点，她还是一窍不通。