You can use your brain to remember the password and record it on a paper notebook or a computer without an Internet connection, but remember to save it. Once you lose it, your wealth may be discovered by others.
Don't rely on your "brain"(memory) to remember the password. That's is the worst mistake you can make. No matter how good your memory is, don't forget, as you age, you brain starts to deteriorarte (cells slowly dies) and your memory won't be as sharp as it used to be. You will end up either forgetting or mixing up everything and then there goes your fortune. Use your memory, and keep multiple backups, digitally and offline in a safe and secure place!
Just relying on memorization of your password is truly insane since whatever how good you are possibly you will forget that especially if you have so many password saved on different platforms, I'm sure we have so many password set since we are on crypto and registering on many platform like exchange and others are kinds required to make a profits so for that to avoid such dumb mistake is to store our passwords on safe areas like what you recommended and also write it on notebooks is also safe since its away from attackers who stole our account details.