[lordnacho]

I think it's to do with the nature of tests. Exam questions in the mathy subjects are sort of two varieties in my experience. One is simply book proof: here's an equation, here's another one, plug one into the other and rearrange and there's this useful result. Come exam time, you just need to remember the steps and you get points.

You'll think you get it.

But there are questions that are about a deeper understanding. For these there's some point to the question that isn't obvious from just reading. I remember the first few question sheets I got in uni, there would be questions that appeared to have nothing to do with what was presented at all. Only by asking around did I discover what the cryptic connections were. If you don't do the question sheets, you won't see this.