16 Signs To Tell If Your Housemate Is A Serial Killer

10. They Record Everything

Not only do they write everything down, but they make sure that everything is completely organised, alphabetised and structured in such a way that is only decipherable to them. They have evidence to back up every argument you've ever had because of their strict routine of noting things down and recording everything, and you may even occasionally see them looking back over their notes, as if they're revising for an exam on your life.