Yesterday morning was my last exam of the year, and it was a big one. Since I had a low mark coming in, and the exam was worth 60%, doing well was critical. The night before, I had prepared my dual redundant alarm system:
1. Mental alarm: this almost never fails me. If there's something important I have to wake up for, I usually wake up within a couple of minutes of when I plan to, alarm clock or no.
2. Mobile phone: in case my mental alarm fails, I set my phone to play the William Tell Overture at highest volume at 7:30 am.
3. Computer: as an extra backup, I set the computer to play The Imperial March from Star Wars at 7:40 am.
So I felt pretty comfortable going to sleep that night. Until morning comes along. I wake up to the sound of chimes, and, as I prepare to roll over and go back to sleep, a voice in the back of my head tells me I'm forgetting something. Oh shit! I have an exam today! What time is it? It's 8:40, and the exam starts in 20 minutes. So I put on some pants, run to the exam hall, write the exam, and all ends well.
Why had my alarms failed? My mental alarm I can't speak for, but my mobile phone had crashed and given me a White Screen of Death, and my alarm clock software on my computer had some kind of bug where it didn't load the MP3 file properly.
What had saved me? A spam email for Viagra and Cialis, sent at 8:40 am, that escaped Gmail's spam filter, and triggered my Gmail notifier. I'll never complain about spam again.