what do you think of the method diceware (using a bunch of dice words separated by spaces) for creating long complex passwords that can be remembered? E.g. for password manager master passwords, or disk encryption. How does it compare to the method you showed in the course?
Any type of password that is longer than 18 or 20 characters will be very hard to guess by modern systems. Even if you have just words containing a-z or A-Z, it will be very hard to compute 20 characters and can take years to compute the password. So whatever method you use for creating a password will be good enough if you are using more than 18-20 characters.