I think we're all well aware that typical users tend toward overly simple password choices. That's why helpful measures such as password strength gauges and password content requirements have become so commonplace. This is nothing new.
And, although our long-term memory for images and words that we've assigned meanings to is quite good, we don't do as well with passwords, which (ideally, at least) should look like a near-random string of characters. It's another challenge entirely to remember which password to associate with a specific account.
It seems like this is easy enough to solve with a little instruction: have users make up a phrase that has to do with the account, and use the first letters from each word as the password: it's unique, non-dictionary, yet memorable.
Brain cells should be used to remember important things. Most important things are conveyed by i.e. poems. Although nobody learns literature citings by heart in the era of wikipedia, a straightforward way to have a strong password is to pick e.g. the first letters of each line of a poem (aka passphrase you should already know), as described in the man:
When choosing a new password, make sure it's unrelated to any previous password. Use long passwords (say 8 characters long). You might use a word pair with punctuation inserted, a passphrase (an understandable sequence of words), or the first letter of each word in a passphrase.
...then you upgrade to snowy, and later realize that a given lib is not compatible with your favourite password manager and shut yourself out until you manage to restore your access. For generating hard passwords, you might as well go for ssh keys and manage those. But tastes and customs differ...
