I feel the same way about at least one or two of my courses every semester. Case in point - I have my linear algebra final tonight, I know what I need to be studying and how to study for it, but I just can't make myself go to the library.
Ditto. I'm sitting in the university library. Linear Algebra final in 1.5 hours. And I'm reading Hacker News...
I find that having to study something takes away most of my natural desire to learn something. I have a psych final tonight, and instead I'm going through a CS textbook. I bet before my next CS exam I will suddenly be more interested in psychology.