Re: Call me old fashioned
Well, I must admit I did something similar about 20 years ago, by choosing a serial number I could glimpse through the front grille of a minibar-sized SGI server besides me (CPU module serial IIRC).
The rationale was that everybody accessing that server locally needed to know that password, but we didn't want to write it down either. Also losing it wasn't an option, so the barely visible serial number was perfect: Long, letters and numbers, easy to remember, and tied to the machine. Note that server wasn't connected to the Internet and the data it contained was very important to us, but not worth stealing.