I'm deeply curious: why? When virtually every reputable security practitioner on this site and others has echoed the advice to just use a password manager for years, how do you come to the conclusion that you know better than them?
If it sounds like I'm asking judgmentally, please don't interpret it that way. Your experience mirrors that of many others, and if I can understand how this line of thinking happens then maybe we can find ways to combat it.
This is just one battle amongst many where, despite endless warnings and examples to the contrary, people seem to think they are qualified to go against encouraged practice for password storage, password management, encrypting data at rest, encrypting data over the wire, etc. And in almost all cases, people come to the conclusion that they know better, when they absolutely do not.