Collusion

I'll tell you a secret; finals are optional if your class is graded on a curve.

My game theory class successfully made an agreement to all not take the final.

If you're wondering what game theory is, it's basically the study of why this kinda stuff should never happen. The difference in this situation was, what people had to lose by not taking the final was not nearly as much as they had to gain by having a story like this to tell everyone they know.
In case you're wondering, I'm the one with the blue jacket, on the left side of the picture, grinning like he just got away with something.