OK, so how do you build a strong password?
Start with a normal phrase that means something to only you so yu can remember it. Do not use common quotes from books or other cultural artifacts. Write it down, including spaces.
For example, if the phrase you use is:
Super best phrase of pass that only I can remember
Add capitalization in odd places
SupEr best pHrase of paSs that Only I caN remember
Add numbers
SupEr7best90 pH32rase of paSs th00at Only I c4aN rem9ember
Add special characters (!#$)(*&%<>?":{}][,./;@).
SupE$r7best90 pH32&rase" of paSs: th00at 0,nly I c4aN re;m9ember
That looks too hard for me to remember so I'll simply
SupE$r best90 paSs:
I'll type it into a window that will not save my work but will allow me to read what I have typed a few times to engage muscle memory.
SupE$rtest90paSs:
After typing it a few times, I have an idea of how I usually mess up typing the passphrase, which I use as part of my memory of how to type out the passphrase. Destroy the written copy of this password-generation process that we started with. Now you have a strong passphrase that you can remember.