1. You know the times of day your roommate is in your room or apartment because you are probably with him or her. 

2. You eat meals together all of the time, except for the occasional necessary dinner with different friends in the attempt to maintain other relationships.

3. Because of this, you know what he or she eats at every dining location on campus.

4. You have an innumerable amount of inside jokes that will confuse anyone else.

5. You know the general location of your roommate at all times. You two may even share locations.

6. You share many, or most, of the same friends.

7. When neither of you are there, those friends know and refer to you as [Roommate 1] and [Roommate 2], rarely separately.

8. The amount of times your roommate appears on your social media is significantly greater than any of your other friends.

9. If you have not seen your roommate all day, you have probably texted each other at some point, because something made you think of him or her.

10. In some way, your roommate has acted as your parent, therapist, significant other, sibling or best friend whenever you needed one.