Gym Bag

What exactly is in that bag man? You come in here everyday and do a workout and you carry a full jansport backpack around with you the entire time. Is it a change of clothes? Sweat rag? Steroids? Hand held mirror? Are you not aware that there is a locker room with at least 100 places to store excessive items? You're not alone though. There must be at least 6 guys in the gym with bags who would consider themselves hardcore enough to be bag carriers. Why? A full backpack? I dont get it.