You could think of these as two companies producing bottled water and now we're going to get hundreds of letters saying not all bottled waters are the same, especially from Italians and the French, but never mind. Let's just pretend that they are.

把他们想象成两家瓶装水厂商吧,我估计我们会收到数百封信件,告诉我说不是所有瓶装水都是一样的,尤其是从意大利和法国寄过来的那些,无所谓了,就把它们想象成是同质的吧

耶鲁公开课 - 博弈论课程节选