...people who say they will buy your textbooks and then when it's too late to sell them to someone else they message you saying "I don't need them"
...profs who tell you that you have a one page limit to answer two questions only to grade it and tell you that you didn't explain something. If you wanted it to be fully explained you wouldn't make it a one page limit and have two questions that need to be on the same page.
...waiting for the rest of my classes to start so I can finally get my calendar organized..
...vague essay questions.