In every group of roommates, someone eventually emerges as the one who is basically mom. They just somehow have a level of knowledge about life that the rest of you haven't quite figured out yet, and when you turn into an absolute child, they yell at you until you act your age. This maternal figure in a living situation is essential to making sure the other members of the apartment don't completely implode on themselves because they're not sure how to adult at this point in their lives.
Sometimes you make terrible life choices and when you tell her, you expect mom to give you a disappointed look and tell her that she's in charge of all of your decisions from now on.
You completely expect her to tell you when what you're wearing looks bad and not to let you leave the apartment looking like that.
After a long night of drinking, laying on the floor always seems like the best option, regardless of where that floor is and how gross it might be. In your groggy haze, you look up and say "Mom, is that you?" No. It's your roommate yelling at you to get off the floor and into your bed.
Once she gets you to get off the floor and into your bed, she brings you water and crackers to make sure you'll be OK in the morning. This also applies to any other time you might be sick, and she supplies you with medicine until you feel better.
You know you would starve without her cooking, and it's actually very reminiscent of the way your real mom cooks.
It's already been well established that she needs to have a place for you to live in her house when she's a successful adult one day because you've realized you just can't live without her.
