|Agreed, they may not let you reuse the old password exactly as it was until you have changed it 3 or 4 times or so many months has passed.|
You can however use a modified version of your old password like adding a number or letter or two (beginning, middle, or end) or changing a letter to a number or number to a letter. This way you can easily remember it but it passes security checks.
You will have to enter your current password to change it so the process is still secure and anyone knowing your old one cannot change it behind your back.
You have to be a little bit crazy to keep you from going insane.