I have exactly that. It can be from highschool or university but the setting is always the same - there was some class that seemed easy, I took it for granted, didn't attend, and now only a few classes left before the end of semester and I am facing a dilemma: I haven't done anything, I am afraid of confronting the teacher who might not even know me, and I am uncertain if I can still make it or if it's already too late and I failed the class.