1. I'll Only Play For A Little While
You tell yourself you'll just play for an hour. You have other things you need to do, but you can afford to give yourself a small break. You won't play for that long. Really, it's fine. You're just going to drive around a little while in GTA 4, maybe drive on the sidewalks a bit and run some people over--but then you see a real nice car you just HAVE to have. You steal it, but a cop is nearby and they see, so you have to escape while trying not to wreck your car entirely beyond use. You just need to get to the nearest pay-n-spray without catching on fire. That pay-n-spray is near a mission, so you decide to go ahead and do it. It won't take too long. It'll be just this one. An hour and a half later, when you look at the clock, you tell yourself you're just going to finish one more mission, just going to play to the very next checkpoint, and then you'll stop. You get to that next checkpoint, but you tell yourself that it didn't take very long at all, so you should just do one more. Three hours later, you're still playing. You look at the clock and realize it's way too late to get anything done now. You tell yourself, "Oh well, I didn't really need to do those other things." And you keep on playing--that is, of course, until GTA 5 comes out.