Commonly occurs when one has been slacking off/not studying hard enough in college, resulting in a poor grade on an exam. This may be due to frequent and out-of-control substance abuse, and/or generally laziness. One then feels the need to study very hard to make up for this lack of effort, even if exams have passed. (Occurs for 1-2 days, at most)
Jim: So did you get your astronomy exam back?
Matt: Yeah, last night. I got a B but Kevin got a D+; ever since then he has been studying really hard.
Jim: Study guilt: don't worry, it will blow over by tomorrow.