I think the one time I beat the game, I might've had like 3000 HP at the end. 9999, let alone 64k sounds just insane.
In the remakes, I've hit the max cap (9999/999) even before Minwu leaves the party numerous times, and usually in less than 15 hours of grinding (which is very normal for me). I don't even bother to grind like that in the NES version because I know about the rollover glitch, and it ruins the experience for me. Everyone plays games for different reasons - most people play to experience the story or overcome some sort of gameplay challenge. I play to mindlessly raise characters' stats.