Hmm - "None can remember a password like "J4fS<2", which evidently mean that it will be written on a post-it note."

Tend to disagree. I've been able to remember passwords incorporating 1-3 symbol characters for better than 25 years, without writing them on post-it notes. What it takes is another potential insecurity - settle on a symbol, settle on a typical sequence of letters and numbers, and settle on a contrary sequence of letters and numbers, said sequences meaning something only to you. You can then vary these sequences over time and mandatory password resets. This becomes potentially insecure if you allow anyone to watch you enter a password, or someone can get a keylogger on your system - you'll need to change your sequences.

Better still, I like two factor authentication, something you have like a smartcard, your thumbprint, a secure token, and something you know, like a password. Either the token or the password won't get you in, you need them both. That has also worked for me better than anything else.