学到的第一课是，教训是可以吸取的。

The first lesson learned is that lessons can be learned.

youdao

这可能不是大多数毕业演讲的人会说的话，但这是成长的第一课。

It's probably not something most graduation speakers would say, but it's the first lesson of growing up.

youdao

在这里，我学到了我的第一课：虽然我不擅长语言，但我仍然可以很聪明，用粘土很好地表达自己。

Here I learned my first important lesson: disabled as I was in language, I could still be smart and well express myself with clay.

youdao

And my plan was going along fine until something happened, and what happened was that chemistry was just way more interesting than I anticipated.

但我觉得最好在第一学期就把化学课选了,所以我就这么干了,我的计划一直都很顺利,直到我发现化学比我想象中的要有趣的多。

麻省理工公开课 - 化学原理课程节选

I announced on the first day of class that I don't, myself, believe in the existence of a soul.

第一节课上,我就声明,本人并不相信灵魂的存在

耶鲁公开课 - 死亡课程节选

Introduction to New Testament History and Literature: Lecture 1 This is Introduction to New Testament History and Literature.

新约历史与文学导论，第一讲1,这是新约历史与文学导论课。

耶鲁公开课 - 新约课程节选