I'm taking upper level classes, and had an issue where the professor asked me to recall some information from an old math class. I had to be honest with him, so I told him straight up in front of the class: "I took the class and passed it, my passing of a class is not mean I actually remember or understand what was taught. While I do have an interest in math, I struggle with it and forget what I don't regularly practice. I can't afford to constantly retake classes, and as such I have sacrificed my ability to know X subject in math in exchange for the passing grade I got"

I can't be regularly be practicing all levels of math and reviewing on top of my regular class schedules and work....I literally don't have the time, mental energy, or ability to even remember any of this stuff.