We had a system at work where you had to change your password every three months and could not reuse characters from your previous password. It had to have letters, numbers, and symbols. My roommate could never remember his password so he wrote it down on a piece of paper and put it under his keyboard. Try explaining that to an IT nerd you will be wasting your breath.
It did help sometimes. He was off sick and we needed to access his computer. I fixed it by looking under the keyboard! I hacked Ito his entire system in five minutes.
We now have a different system and while you still have to change the password every 90 days, you can use the core of the old password but amend the number within the password.