It doesn't even have to be truly random, just "random enough". If you were to use a passphrase like "Use 5 or 6 words and the problems listed here vanish", that

It doesn't even have to be truly random, just "random enough". If you were to use a passphrase like "Use 5 or 6 words and the problems listed here vanish", that wouldn't be random per se, but for an attacker it might as well be.