Either it’s simple for you and anyone reading one or two of your leaked passwords, or it’s not, you can’t have simple obfuscation rules that still work after a password reset or two and aren’t easy to reverse engineer. You can’t have complex rules that are hard to figure out for potential hackers, but easy to remember across password resets and multiple sites.
That is, unless you write them down in a secure place, and then you make some application to fill them for you in your browser and… you just invented a password manager
you’re literally just remembering 1 password and some simple rules to obfuscate it.
people used to remember multiple whole phone numbers without issues.
Either it’s simple for you and anyone reading one or two of your leaked passwords, or it’s not, you can’t have simple obfuscation rules that still work after a password reset or two and aren’t easy to reverse engineer. You can’t have complex rules that are hard to figure out for potential hackers, but easy to remember across password resets and multiple sites.
That is, unless you write them down in a secure place, and then you make some application to fill them for you in your browser and… you just invented a password manager