I don't remember if I beat the second quest in Zelda 1 when I was a kid. I probably did, but I'm not certain.
I bought the Virtual Console version 4 years ago, when Wii was brand new and there were only 5 NES titles to download. Since I've been playing it infrequently, the first quest of Zelda took about a year and a half to complete.
Last week, I was still on level 4 of the second quest. But I played it early last week, and my 3-year-old started to take interest. His favorite things to do were to spin around and fall down when I died, wave his toy sword at the screen whenever a monster was on it, and talk endlessly about secret passages.
It dawned on me too that secret passages are so much more fun when there's one in every single screen of a game, and why don't more games hide an endless array of them like this old, tried-and-true classic? It seems like the newer Zelda games even only give you a few boulders here and there, clearly marked, spaced by vast regions that do little more than ensure that the area takes a little longer to traverse.
After beating the second quest, another fun thing happened...I got my 3-year-old to start up his own game. For the last week he's been cheerleading my playing, but upon starting his own game, he built up from not knowing even how to walk up, down, left, or right, to actually walking around while hitting the sword button and watching the screen all at once in 45 minutes...And he's never played a game that long before (unless you count dancing to Beatles Rock Band). I'm excited to see where this kid goes now that his attention span and skill is finally developed enough to handle Zelda.