You completely dodge the point that if you don't use a password manager then you must use relatively weak passwords because they must be memorable as must the user identifiers. One of my password stores contains 98 passwords, the other contains 110. They almost all have completely random passwords with 48 bits minimum entropy and most of the user identifiers are also random strings (or email address with random user parts) with a minimum of 48 bits of entropy. That's a lot of entropy, certainly more that anyone normal could remember.
"Must" is too strong. Have you never seen one of these?
You don't even have to write down the random letters you use, you can use letters picked (systematically) from a novel or other book. The mind is a critical keystore (it's the only one that requires your volition to unlock it) but it should be used to key into larger sets of data.
How strange to post an image of a notebook, but to omit to quote the last paragraph of what I wrote:
All the people I know or know of in the infosec business recommend using a password manager, and wherever possible using non-memorable random passwords. Bruce Schneier even once went so far as to say that you should write strong passwords down on paper in preference to using ones that are memorable but weak.
In case you don't recognise the name, Bruce is possibly the foremost cryptologist regularly writing for consumption by the general technical community. He was one of the submitters, and finalists, for both NIST competitions that led to AES and SHA-3. When someone of that calibre offers advice I'm going to listen to them.