It can completely and entirely fuck your Monday in the arse.
So maybe I shouldn't have bragged so much in the previous post. I was having a lot of trouble logging in at work yesterday and the ops guy and I spent an inordinate amount of time trying different things trying to get my remote machine to talk to the AD server and authenticate. (We found a workaround this morning when I authenticated through a differerent domain controller.)
In the process of this mess, I decided to reboot my local machine just in case it was something wrong on my end. I sincerely doubted that because I could RDP into other machines outside of our network, and I could authenticate with Lync (which server is in the other office where the other domain controller is).
So I rebooted, and the machine absolutely refused to boot back up. It kept dying right after it enumerated the RAID drives (and sometimes it didn't even get that far). So I spent three hours yesterday trying to figure out why that had broken. At first I thought one of the mirrored drives had died. That wasn't it. Then I thought maybe the external backup drive had died and was somehow affecting the bootup. That wasn't it. In the end, I disconnected all of the USB-attached peripherals, reattached both of the mirror drives, and tried again.
That time it worked. Booted right up like there had never been a problem. So I started adding USB peripherals back to see which one might be hosed. Turns out I put them all back (even updated the firmware and control software for one of them since it came up when I plugged it back in) and it's still running.
Beats the hell out of me.