bitflipper
I once had a customer site that, as a military contractor, had to be ultra-secure. Passwords had to be changed weekly, and were computer-generated random strings of text.
Sounds secure, but when I went into their offices early one morning on a service call I noticed that at every single desk there was a post-it note stuck to the side of the display with that user's password.
I once worked in a place with a similar password policy. Not military, but an environment where internal fraud prevention was a big thing and it was regarded as most important that no-one could log on to someone else's account. Passwords being changed by the server every 28 days to things like "djduk4859JDHSI----&98jdj", with dire warnings never, ever to reveal the passwords to others or write them down.
As you say, almost every monitor had a post-it note stuck to it. And if you called the IT help people part of the security check was to tell them both your user name and password, the two things they needed to log in as you...
The other extreme was when I was working for a British local authority. One day an IT dept. memo to all 10,000ish employees said "Passwords are meant to be difficult to guess. So we are a bit concerned that one third of you have chosen the nickname of the local football team as your password....."