Lack of Understanding

He's out of his depth in that advanced physics class.

When will the project be completed?Your guess is as good as mine.

I think you've got the wrong end of the stick.I didn't mean it that way.

I don't know beans about car engines, so I rely on the mechanic to explain what's wrong.

He couldn't remember the name of the movie for the life of him.

封闭的书, 谜

The workings of the stock market are a closed book to me – I don't understand how it works.

股票市场的运作对我来说是一本封闭的书——我不明白它是如何运作的。

His instructions for assembling the furniture were clear as mud; I had to figure it out on my own.

For scientists, the nature of consciousness remains the final frontier of human understanding.

I've been so busy lately that I'm in a fog when it comes to my schedule.

I can't make heads or tails of this manual; it's so poorly written.