Unix is great because everything is a file. Except when it's not so great. By far the best part of the article: "The one really memorable “Oh sh-t” moment was

Unix is great because everything is a file. Except when it's not so great. By far the best part of the article: "The one really memorable “Oh sh-t” moment was literally very early on in Linux development, when I realized that I had auto-dialed my main harddisk when I meant to auto-dial the university dial-in lines over the modem. And in the process wiped out my then Minix setup by writing AT-commands to the disk that understandably didn’t respond the way the autodialling script expected (“AT commands” is just the traditional Hayes modem control instruction set). That’s the point where I ended up switching over to Linux entirely, so it was actually a big deal for Linux development. But that was back in 1991."