You can very quickly drive yourself nuts by sitting down, thinking, oh, I can write this program, no sweat, and then you write it and then there's a tiny little mistake here, but then there's a tiny little mistake here and here, and all of these stupid little things cascade until you try running your program, and the thing just doesn't work.

如果你只是仅仅干坐着，不费吹灰之力，凭空幻想着我可以把这个项目搞定，你会想地发疯的，也许你会写出一点东西出来，可能会有一点点错误,紧接着这或那又出现一点小错误，这些小错误一点一点地堆积了起来,直到你开始运行你整个项目，你会发现这堆东西根本就不工作。

哈佛公开课 - 计算机科学课程节选

Here are humans who had to walk long distances potentially to find the food, kill the food at great risk to themselves; inspiring a cascade of physiological effects that have to do with fear and arousal and things like that, not to mention all the calories one would burn doing this kind of activity.

这些人可能需要走很远的路,去寻找食物,冒着巨大危险,杀死猎物,人们耗费能量以激活一系列生理效应,用以战胜恐惧,引发斗志,更不用说人们在狩猎的过程中,消耗的卡路里量了

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选