Nakago: And I’ve got something even more interesting today. This is the first dungeon map ever created for Zelda.
Tezuka: Basically, we were going to make lots of dungeons using one square per room, and lay them out like a jigsaw puzzle.
Nakago: Right. Tezuka-san said, “I did it!” and brought this to me. I created the data exactly in line with it, but then Tezuka-san made a mistake and only used half of the data. I said, “Tezuka-san, there’s only half here. Where did the other half go?” and he was like, “What?! Oops, I messed up…” But Miyamoto-san said it was fine just like that.
Tezuka: Heh heh heh. (laughs)
Nakago: So, using the half of the memory that was left over, we decided to create the Second Quest20.
20Second Quest: A second adventure of greater difficulty prepared for players who had cleared the original quest in The Legend of Zelda. When you play this quest, Link on the select screen changes so he’s holding a sword.
Iwata: Huh? Just wait a second. If Tezuka-san hadn’t messed up, there’d have been no Second Quest?
Nakago: Yes, that’s right.
Iwata: Whaaat?! (laughs)
You know, I'd prefer more dungeons over an extra difficulty any day. Why not make this a Wiiware release? (read: never)
You can read the interview in its entirety here. Lots of fascinating facts about Zelda!