鬼知道

鬼知道:

Literally means:

the ghost knows; nobody knows.

Actually means:

It literally means no one else knows about something except the ghosts.

It figuratively means knowing nothing about a certain matter.

It has a connotation of having no choice or being discontented.

鬼知道，除了鬼以外，谁也不知道。

表示对某件事情的一味切情况完全不了解。含有无奈或不满的意味。