A middle-aged man who works at the market complained that it made no sense to him why anyone would put a bomb in a crowded vegetable market: He said that all the traders and sellers were going about their business when the explosion took place.

VOA: standard.2009.06.01

And part of it is mystical-- still not understandable-- but we are going to talk about as much as we know-- why it works and how it works.

一部分是很神秘，仍无法理解-,但我们会谈到我们所知的-,信念为什么会起作用及如何起作用。

哈佛公开课 - 幸福课课程节选

Why? Because it works.

为什么？因为它有效。

哈佛公开课 - 幸福课课程节选