I'm stubborn in the persistent type way so usually when a game is hard, it makes me want to play even more. I love a challenge.
On the other side of the spectrum though, there's been a LOT of times where I'm playing a game, stop playing for a day or so and then all of a sudden, I realize that months have gone by and I stopped 75% of the way through the game. Of course at that point, you don't want to pick up where you left off since you don't remember once and would rather just start over but then you forget to. Confusing, huh? I gotta work on that lol