That depends on how much sleep you get but dreams leave fragile memories. They fade quickly.

这要取决于你一晚睡多长时间,梦境会留下一些若有若无的记忆，而且很快会淡忘。

耶鲁公开课 - 心理学导论课程节选

Archaeologists in the nineteenth and twentieth centuries were stunned to find the ruins and the records of remarkable peoples and cultures--massive, complex empires in some cases, but some of which had completely disappeared from human memory.

十九和二十世纪的考古学家们,震惊地发现了,古代伟大名族和文化的遗迹，有些还是大规模，复杂的帝国遗迹,但也有一些就完全从人类记忆中消失了。

耶鲁公开课 - 旧约导论课程节选

We say that we have very very short lives, because after all right now I've got some memories that I didn't have 2 hours ago.

我们的人生非常短暂，我现在就有一些,我2小时前没有的记忆。

耶鲁公开课 - 死亡课程节选

I have some memories I didn't have 20 minutes ago.

有一些我20分钟以前,没有的记忆。

耶鲁公开课 - 死亡课程节选