Oh I believe it. I would have kissed the ground to get a C in that math class, so I could have moved on to algebra, which was easy for me. Learned it in my math anxiety class, lol!
We had an exercise called "peer editing" in English. If it were one of my kids, I would have taken a red pen to their rough drafts. A couple of papers would have bled red ink, but I felt very uncomfortable doing that, so I tried to pussyfoot around and work with them. Mind that I am old enough to be their mom. I had the advantage of 5 yrs of Catholic school back in the '60's. Wish my folks hadn't put me in public school.
If you saw some of the work that was turned in, and my kids are no exception unfortunately, you'd wonder exactly what kids do in school all day.