And that process continues, and you immediately start to realize how strange this is.
随着课程不断推进，你会突然间发现，这种感觉不太对劲。
I didn't know 25 percent of the more foundational thing, and now I'm being pushed to the more advanced thing.
我明明还有25%的基础知识不懂，现在却被逼去学更加深奥的东西。
And this will continue for months, years, all the way until at some point,
这会持续数月或数年，直到某一个时间点，
I might be in an algebra class or trigonometry class and I hit a wall.
我可能会在代数或是三角函数课堂上完全不知所云了。
And it's not because algebra is fundamentally difficult or because the student isn't bright.
这并非因为代数学本身很难学，或者是因为学生不够聪明。
It's because I'm seeing an equation and they're dealing with exponents and that 30 percent that I didn't know is showing up.
而是因为当我看见指数的等式时，其中有30%是我不懂的知识。
And then I start to disengage.
然后我就不想做了。
To appreciate how absurd that is, imagine if we did other things in our life that way. Say, home-building.
为了让大家体会这是多么夸张，可以想象一下，当我们在人生中以这种方式干其它的事情时，比如，造房子。
So we bring in the contractor and say, "We were told we have two weeks to build a foundation. Do what you can."
我们找承包商来，然后和他说：“我们被告知只有两周时间去打地基。所以能建多少就建多少吧。”
So they do what they can. Maybe it rains. Maybe some of the supplies don't show up.
然后他们就尽力去做了。中间也许下雨了。也许有些物资没到位。
And two weeks later, the inspector comes, looks around, says,
两周之后，房屋检查员来了，看了一下，说：
"OK, the concrete is still wet right over there, that part's not quite up to code ... I'll give it an 80 percent."
“看起来这儿的水泥还没干，那块儿也还不大行……我就给个80分吧。”
You say, "Great! That's a C. Let's build the first floor."
然后你们说：“太好了，至少还是个C。我们开始建第一层吧！”
Same thing. We have two weeks, do what you can, inspector shows up, it's a 75 percent.
同样的事情接连发生。我们又努力了两周然后房屋检查员来了，给了个75分。
Great, that's a D-plus. Second floor, third floor, and all of a sudden,
太好了，居然还有D+！继续建二楼，三楼，
while you're building the third floor, the whole structure collapses.
直到建第三层的时候，整栋建筑突然倒塌了。
And if your reaction is the reaction you typically have in education, or that a lot of folks have,
如果你的回应与上学时的回应一样，或者是很多人会有的那种反应，
you might say, maybe we had a bad contractor, or maybe we needed better inspection or more frequent inspection.
你也许会说，估计是承包商不够格，也可能是检查力度和次数不够多。
