Assignment Again Attempted

Today I found out the assignment for calculus I did the other day was really due tomorrow. This meant I had to do the whole thing over again because I turned it in when I was supposed to have turned in another assignment. At least this time, I actually sort of knew what I was at least trying to do for most of the problems unlike last time. I have my first calculus test on Tuesday. I wish I felt ready for it, but there is a lot of studying I should do before that time and not much time to do that studying. Why am I taking calculus again?