But after his first ride, Wiley Post knew that flying was something he could learn to do.

VOA: special.2009.03.18

If you don't do that, there's a danger you will learn something you don't have to, and we don't want that.

但是如果你不来,你就有可能学到一些不重要的知识,我们当然不希望这样

耶鲁公开课 - 基础物理课程节选