You don't know half of it.

我是你的朋友，你不能如此对待我。

youdao

You think you are smart. You don't know half of it.

你以为你聪明，其实你半点儿也不懂。

youdao

Stryver, preparing him with ostentatious friendliness for the disclosure he was about to make, 'because I know you don't mean half you say; and if you meant it all, it would be of no importance.

因为我知道你对自己说的话连一半也不当真，而且即使全部当真也并不重要，所以我就先来个小小的开场白。

youdao

Son, you don't even know the half of it.

CNN: Going after Clemens stupid, political