My best friend and I spent a summer playing through his grandma's NES collection, and we got deep into Star Tropics. Loved it, up until the part where you needed a code from the instruction booklet. His grandma had thrown away everything but the games for efficient storage, so.. there it was, that game was done.
We moved on to the original Zelda, were getting confused finding our way around after the second or third dungeon so we dedicated a day or two to mapping the entire map out in a sketchbook, screen by screen, until we had it all. And then set off to playing through the rest of the game. Got all the way to the point where we needed to go to Ganon's dungeon, and could not for the life of us figure out where to bomb for the entrance. We got
close, too, just never put a bomb on that one specific tile.
It was before the web or GameFAQs or anything like that. The summer of giving up on games.
Epilogue: decades later he was home on leave and his grandma's house had been cleaned out so he got all her games,
including a Game Genie," and we decided to play through Zelda and actually beat it this time. I literally was like "Dude, I googled it, I know where to bomb now." 
So we decided to use a take-no-damage code with the Game Genie so we could easily breeze through it in one night just to say we finally did it. We stayed up extremely late and actually managed to get from the start all the way to Ganon's dungeon in one sitting, meandered our way through the dungeon, and eventually accidentally stumbled across Ganon.. without first picking up the Silver Arrows. We couldn't damage him, and since we never died and *couldn't die, we had no way to save.
So to this day we've still never beaten the original LoZ. And considering the efforts we put into that and what ended up coming of them, I actually kinda don't want to. I think it's a better story this way.
I recall even waiting for reruns of early Johto episodes of the anime in hopes of getting a hint, to no avail. I eventually just restarted the game and ended up getting through with zero issue, amazed at the fact I didn't think of just... walking further down the path before. Fast-forward to the Elite Four, where I realized too late I could have trained the other Pokémon in my party. I beat the game, Red and all, on the third restart.
