The alarm that didn't ring

I woke up at 5:55 a.m. today and had to be at work at 6:30. I don't know why the alarm didn't go off. I am almost 100 percent sure I set it before I went to bed. I checked right now and it was indeed set to 5 a.m. Did I turn it off while I was sleeping? Anyway, I was suprisingly less panicked than I expected. I had already taken a shower the night before. I just didn't do some of the things I usually do before work, like eat breakfast, make a lunch, read the paper, and put on make-up. I was 7 minutes late to work, whereas I'd usually get there 5 minutes early. I woke up late and it wasn't the end of the world. Imagine that.