I don't know most of my passwords. That is, I don't rely on my memory to keep them organized.
My password manager keeps my 100+ passwords encrypted. When I need one, it prompts me for my master password, decrypts that password, and copies it to my clipboard.
What's more, I can generate long random passwords for each account. This lets me have a unique password for each account without any memorization.
If one of these passwords get stolen, I only need to reset one password. And since they're unique, I can be confident that the rest of my accounts are still secure.
I used to memorize all of my passwords. But that encouraged me to keep passwords short and memorable, as well as reuse passwords. As the number of accounts I used grew, the more often I would forget passwords. Especially for accounts I used infrequently.
Now, I'm confident that even if I neglect an account for a year, my password manager will remember.
Stop trusting your memory with passwords. Any password manager will be better than your memory.