We did that during the Great Depression, when it suddenly seemed like we really needed to do something.

是在大萧条时期开始实行的，因为当时我们突然发现,确实该做点什么了。

耶鲁公开课 - 金融市场课程节选

This is great when you want to express regret for something that you perhaps did not do.

当你想表达对一些过去没做成的事情感到后悔时，你可以使用这个句型。

I should have 课堂 - SpeakingMax英语口语达人

Whatever you think those are. Here, you might imagine different people disagreeing about-- oh, but throw in something--but if what you want to do is write the great American novel, then you've got the experience of staying up late at night not knowing how to make the plot work out, crushing pieces of paper and throwing them away.

你能想到的都在里面，可能有人不同意-,插入某某东西，比如你想,创作最伟大的美国小说，于是你获得熬夜的体验,纠结于如何构建情节，撕碎稿纸，扔在一边。

耶鲁公开课 - 死亡课程节选