[He has to because he made a promise to a princess/queen that he's massively in love with that he'd return to her alive.]

Well, you're right. It doesn't. From what I've found out, we haven't uncovered a lot so far. For all I know, it might mean thinking outside the box somehow. Either way, the fact that none of us have found much hasn't stopped others from trying. [Keith seems to be one of them, from the conversation Zidane's had with him anyway. He could be wrong but that was the impression he got.] No matter how long it takes.