I'm glad they got caught. That will 'teach them a lesson'! [=they will learn that they should not do that again]
We 'learned our lesson' the hard way. [=we learned from an unpleasant experience]
They studied the 'lessons' [='teachings'] of the great philosophers.
(..) so tired lately. But I-- I was pushing myself too hard. I know it. I just don't want you to worry. I learned my lesson. Well, um, what's the... What now? What now is that we go on. Like always. Right? (..)2013 TvShow: Breaking Bad Title: Confessions Season: 5 Episode 11