Partly the guardians really are just animated corpses. They have an intelect but it's ben canonized they have no memory. So. If hawthorn kept her memory she'd be unique in that regard... One thing is that we don't know what happened to the Speaker. Second is we don't know if what he said was true..... I think a better answer to the question of what makes a Guardian worthy is one simple word. "Fear." Ghaul says that The Guardian is not brave, they have simply forgotten the fear of death..... But that is the irony. That is the thing Ghaul can never understand... That it is fear that makes them worthy. Courage isn't being unafraid. Courage is fear it's self. Courage is to fear of what happens if you do nothing. Losing something you mustn't lose, to fear failing something which you must not fail, to fear living, knowing you let someone else die. If you boil it down to it's very essence, you will always find the same four words when dealing with someone who has risked their life for another. "Because I was afraid." Courage isn't the absence of fear, it isn't the conquering of fear, it is fear, the fear of failure, and it is a fear that will drive you to move when all reason tells you to be still. It is to fear something more than you fear death. Ghaul is driven by hunger for victory, and recognition.... He could never understand being afraid for another, or dying for them. Thus, he could never be chosen. I have always felt that Guardians are chosen from people who gave their life defending others.... People who were so afraid of failing others that they'd sooner die fighting. Guardians. So why are guardians worthy? Not devotion, sacrifice, death... It's much more simple.... They are chosen, because when they died, they died afraid of what would happen if they didn't act.