And for reference, incidentally, in case you ever forget what the point of some exercise was, I'll almost always comment the code up top with a quick sentence or two that reminds you what this program does.

顺便作为参考，为了避免我们可能忘记一些代码的意思，我通常会用一两个简单的句子,在上面作出注释,那样会提醒我们这个程序是干嘛的。

哈佛公开课 - 计算机科学课程节选

It used to be the case-- I forget how long drive-in windows have been around, certainly as long as you guys can remember-- but there was a time when drive-in windows didn't exist.

曾经是这样的情况,我忘了免下车餐厅已经出现多久了,当然可能自打你们记事时就出现了,但是在免下车餐厅尚未出现的时候

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选