So you're playing a game or are planning on getting back into one. You're making all these plans in your head about what you're going to do and the best parts of the game, when you realize that you're up to that one part of the game. That one guy or boss or level that's a real momentum killer.

I had a late start at work last week and thought I could kill a half hour before hand on Skyrim. Figured I'd sell some stuff or raid a bandit camp or something. It wasn't until the loading screen that it hit me: I have to talk to Paarthurnax for the first time. Guess where that half hour went.

Any parts in games that make you think "Oh God not this again"?