It's a cute idea and I love the concept from XKCD, but the best practice is just to use a password manager and stop trying to remember passwords (and absolutely never reusing passwords).
- you need a password for your password manager
- you also need a password for your actual desktop/phone, when the manager is inaccessible.
- you may have a work computer requiring a different password as well
Here are already 3, ideally different, passwords you need to remember.
Although after a couple of days of using a new password regularly, I can't help but have it memorized anyhow.