Great, Now We are 100% Locked Out

I live in a five bedroom apartment, so for the non-math whizzes, that means I live with four other people besides myself. Tonight only four of the five inhabitants were home. Three of us were sitting in the living room watching TV and chatting, the other was studying. Two of my roommates decided to order pizza as it was cheap Tuesday. I agreed to walk to the pizza place with them. As I left my room I said to one of my roommates (Ying) to bring her card, because I did not have mine, to get into our apartment. (To get access to our apartment you must get through one main door, that other apartments have access to and then through our actual apartment door up a small set of stairs and you use an access card for this.) She said we would make Cassi bring it (Ying and I always forget our cards and Cassi always has to let us in.) So we notified Cassi to bring her card, she rolled her eyes and said, "it is always me with the card." Well anyways the three of us set out to the pizza place. Once we arrived, Cassi realized that she had not indeed brought her card.... So we teased her, but we knew it would be OK since we still had one roommate home to let us in. As we rang the door bell to have Jennifer let us in I jokingly said, "wow, 75% of our apartment is currently locked out." As Jennifer exited our actual apartment door and started descending down the stairs to the other access door her face dropped when she realized that she had forgotten her card and now we were let into the front access door but locked out of our actual apartment. As soon as I saw her face drop I said, "great, now we are 100% locked out." We all proceeded to laugh and had to call one of the RA's who I am sure did not appreciate being called to duty at 9pm at night because an entire household was careless. The moral of the story is to always bring a key/card. Or if you prefer a proverb, "measure twice, cut once," aka check twice to make sure you actually have a card.