Worst. Idea. Ever. Possibly even worse than a post it attached to your screen, but only if the person leaves the notebook on top of his desk for all to see.
Better off using passwordbox.
I have so many odd logins for so many weird sites, that I do keep a book, but never near the computer.
And each book comes secretly installed with a GPS locator chip.
I use an excel document that itself has a password…
…and a small explosive device that detonates if you don’t say the codeword “lemons” within 3 seconds of opening it
Better yet, hollow out the inside ala Shawshank and install a camera with a trigger set to the opening of the front cover.