don't know how i missed this.
"the zone" that you are describing is in no way exclusive to video games. i'm sure you're seeing it in that context if only because you're using a game boy, but it is just a very focused mental state. it has nothing to do with not making mistakes, it has to do with inspiration and more or less being in the right place at the right time. same thing happens with music and any other instrument or program; i've definitely sat down on a laptop and had a song finished in a few hours because i was in "the zone". i know what you mean in describing the similarity to playing certain video games, but it's a feeling/place/THING that came long before the game boy even existed.