I have a similar anecdote. I had a password that was 14 characters long, for a school system too. One day I mistyped it and it still worked. I was puzzled and discovered that it actually took only the first 8 characters into account. From that day, whenever someone was around, I typed the first 8 characters as fast as I could (pretty fast as it was something I typed in quite often) and then I continued to type random stuff like crazy for a few seconds then hit enter and loved to see how people face when they saw it working like if what I typed actually was my exact password.