Building Etiquette

I've lived in my apartment for about seven months now. I recognize very few of my neighbors. So when I'm in the small lobby and someone knocks on the door, I usually let him in. The lobby is the size of a living room, and the doors are made of glass, so it would be pretty uncomfortable to refuse a knock and run out the other door or into the elevator, especially if I then had to worry about passing that person on a daily basis.

I even take it a step further: if someone's at the call box, and I'm heading out anyway, I politely hold the door. I don't discriminate by appearance, keeping in mind that I often look like a hobo on quick trips outside. I don't see how I could just slink out, anyway, and let the door close behind me when someone very obviously needed to get in.

The other day, I ran outside to throw away some pizza boxes wearing mesh shorts and a t-shirt. I forgot my keys. So I stood at the lobby door, looking like a cold, pathetic orphan, and waited for someone to pass by and let me in.

A girl entered from the other door (which is located directly across from where I was standing). I knocked. She pretended not to hear me. I knocked again. She huffed and spun around and looked me up and down. Then she told me to try the call box. I explained that I was a resident, and that the call would only go to my cell phone, which was sitting on my kitchen table. She hesitated for a minute. Then she ran into the elevator.

I can see her point--barely. But there has to be proper protocol for situations like this.