What came later was not remaining friends with Leonard and not knowing why.

后来和莱纳德不再算是朋友了，不知道为什么。

youdao

Strange is our situation here upon earth. Each of us comes for a short visit, not knowing why, yet sometimes seeming to divine a purpose.

我们在这个世界上的处境是奇怪的：每个人，都是来做一次短暂的访问，不知道是为了什么。不过有时似乎也会觉察到有某种目的。

youdao

The living chick in the shell has known no other world. Through the wall comes a whiteness, but he does not know it is light. Yet he taps at the white wall, not knowing why.

活在蛋壳里的鸡雏不知道另外的世界，壳壁透进来一片白茫茫，然而它不知道那是光，只是敲打着白壁，不明所以。

youdao

Whether or not the weather outside is frightful, knowing how and why airlines operate the way they do is a first step in minimizing the effects of travel calamity.

BBC: How to minimise the effect of travel disasters

And President Obama, being such a loyal native of Chicago and knowing what has happened there, why has he not since being President pushed anything on issues of gun control?

WHITEHOUSE: Press Briefing

The FDA should provide consumers with the timeline and all correspondence and phone records surrounding this case to show why a two month delay would take place from knowing the drug did not work to telling the public.

FORBES: A Drug Recall That Should Frighten Us All About The FDA