One thing I figured out early on about doing well at university, determine what the instructor wants and give it to them.
It's Ok to be opinionated, but doing so while still remaining within the instructor's framework is an art that you would be well advised to perfect.
If you enter into an assignment intent on expressing yourself in your own unique manner and damn the consequences you are going to run into professors who will crush you to prove their point. I had an instructor who would routinely axe an entire letter grade from your paper if your headers were not perfect.
It's their world, and unless you want to spend all your free time crying to the dean, get used to giving them what they want. I have no shame so it was easy for me. I don't mind grovelling for a good cause.