Moving in with another person can teach us a lot about ourselves. You might realize some of your own annoying traits, like blaring music late at night or always leaving the toilet seat up, and adjust your behavior to be courteous to your roommates. But you also might learn that you’re a lot more self-aware than the people you share an apartment with, and that if you ever want to have clean dishes or a sparkling bathroom, your best course of action is to just move out.