In the days before memory cards, I always had to do something which usually interrupted my gaming time. Run errands, do homework, visit relatives, and all sorts of other tasks cut my gaming time short. This was very annoying when in the middle of a game that had many levels.
Super Mario Bros. 3 is an example. I knew about the warp whistles and Warp Island, but I wanted to beat the game straight out by playing every stage and every Hammer Brother on every world. No P-Wings, music boxes, or Jugem's Clouds would be used either. One Saturday morning, I was called to go to my grandmother's house. This really pissed me off because I had conquered every stage all the way up to the tenth stage on Iced Land. I wasn't about to turn off my game, so I paused it. As misfortune would have it, I didn't get back to my game until the next day since grandma insisted that I spend the night over her house. For 27 hours, my NES was paused with SMB 3 in the deck.
Have you ever left a game paused for a long while be it purposely or accidentally? How long?