Locked doors and no keys

Oops. So, for the second time in several weeks, I locked myself out of the apartment. The first time was while Benjamin was out of town, and I had to seek refuge at the upstairs neighbor's until the landlord showed up to let me in. This morning I walked out the door, locking it as I went (it is one of those that you can lock without a key, from the inside)...and immediately realized that I didn't have my keys. In my defense, I was being distracted by the cat, and I have a lot on my mind. Luckily, Benjamin was home - still in bed and not happy to be yanked out of the bed by frantic doorbell ringing, but home. Sorry!