Back when I was in college, I had one class where the entire grade was a couple of labs and one midterm and one final, but the exams were weighted like 80% of the grade. The professor stopped showing up for around a month and didn't get the midterm grades back to anyone before the drop deadline for the course, so no one had any clue where they stood in the course.

Had another professor who told constant senile old man stories, and me and my friends would leave in the middle of class and get lunch instead of sitting through it. 90% of the students in the course failed all the exams and there ended up being an absurd curve.

My major was a fallback for a lot of people who didn't get into the engineering areas that required a high GPA for entry, so seeing people drop out or fail classes was super common. My freshman year roommate dropped out, and so did my sophomore year roommate.