My webserver has been down for two days, and I only now noticed, even though I've been receiving notifications, on the hour, every hour, since it went down.
Sigh.
Why didn't I notice?
Because I also receive the same notification (same subject line in the email) from another webserver that tends to go down more often than not, and it too, went down around the same time as my webserver.
I restarted the other webserver and kept wondering why I was constantly receiving notifications of it being down. I figured the webserver might have been updated, thus breaking the status page I check, so I adjusted the monitoring code appropriately (yes, one of the fields I was looking for didn't exist, which lead me to that conclusion).
It wasn't until I tried hitting my own webserver that I actually noticed it was down.
That's when I realized that not having the website name in the subject line of the email notifications was not a good idea.
I also realized I should blog more often.