I just thought about this, because I had such a thing:
A few years ago i played Half Life 2 for the first time. I came to the Nova Prospect (prison) gauntlet (where combine keep swarming in from 4 doorways etc) and i kept dying. I just couldn't make it and after many tries I just turned on god mode, completed the scene, turned god mode off again and lived happily ever after....kind of.
It turned out, it was always in the back of my head as something "left undone". If I talked with someone about Half Life 2 (for example one of my room mates is a big fan ;-)) it came back up, like a voice in my head "Completed the game?! No you didn't, remember that one scene?".
So few weeks ago, I was kind of bored and thought I could play it again. This time I got the scene done in the second try I guess, and it was actually a relief. :-)
So the question is, do you have similar things in any video game, that you are not comfortable with, or that "haunt" you because you either didn't do something or did the wrong way? Could be interesting to hear.
Greetings,
Keex