The reason is because there are two different approaches to deal with illness: one,the positive psychological approach is that the illness is the absence of health, as opposed to health is the absence of illness.

究其原因，是因为有两种不同的方法,对付疾病，一是积极心理学方法,它指的是，疾病相当于不健康，相对地，健康等于没疾病。

哈佛公开课 - 幸福课课程节选

Of course you guys are savvy enough to know this, but a lot of people get fooled because many people believe that a serving is what's ever in a bag, or a bottle, or a box, and they don't look and see how many servings are actually in it.

大家很聪明,当然看得懂,但还是很多人搞不清它的含义,因为很多人认为所谓一份食物就是指,一包,一瓶或一盒内的食物总量,而没看清整个包装内实际上有几份食物

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选