Poetry & lyrics
For many years I've been using poems and song lyrics which have been stuck in my head for decades as the key to my passwords, some of 'em since well before I started school, and throw in a bit of punctuation and a number or three.
One of the first was: Btdatd,Wtnibtl93. How on Earth is that a memorable password? Well I've known the key to it since I was three:
"Between the dark and the daylight,
When the night is beginning to lower"
Now I did have to remember that 93 was the number to finish it off, but other than that It was stuff kicking around in my head anyway.
What gives me fits are systems which insist on ridiculously short passwords: EIGHT characters? Really! That may have been reasonable back in the days when memory speeds were measured in microseconds, but nowadays? Ridiculous!