Last year, we have a quiz that's like 50% of our grade but the teacher announced it before the weekdays on the last minute of our class so my classmates never took it seriously. During the weekdays, I really studied and review the material while my "friends" was going to the mall, playing games, etc.. and they we're procrastinating and just being lazy in general. I told them numerous times that we have a quiz but they basically just said and I quoted: "Don't be boring. It's just a quiz" and "We still have time to review." On the day of the quiz, half of the class failed because they didn't study except for me and few other people. I was happy for my success while they need to retake the course.