I love it when a piece of fiction ends on a happy note. Besides, I can totally relate to this situation.

Once I had been late for an exam cause I stayed awake all night studying that course for the very first time since the semester began. At the end of the day, the exam questions were from the topics I studied the night before. I eventually had a B in that course, though it was the only grade that tainted my perfect result that year.

Nice writing!