Ban "writing down" passwords....
Ever played the word game called hangman? Start with a row of blank "characters" and try to guess the word. So here's a password of mine ....yes.....written down:
P _ _ _ _ Y _ _ _ _ _ B _ _ _ _
There are thirteen blanks....and I can easily fill in the blanks even without any clues. And this example has more than 10** 21 possible ways of filling in the blanks (that's a decimal number with 21 decimal digits). Go ahead.....tell me what my password is. Or...tell me how much time a robot will take to try out ALL THE POSSIBILITIES........and that's assuming the password protects something more valuable than some cat videos!!