I've had a couple of such experiences, the last one I can remember is relatively recent, about three months or so ago when I was absolutely addicted to Allods Online (my first real MMORPG experience, the first one being Star Wars Galaxies but only for two months). Anyway, so one morning as usual I wake up and go prepare my breakfast, I'm asking to myself "can't decide, toasts or cereals this morning...", I then remember opening the fridge and looked at the bag of sliced bread and then told myself "meh I'll pass"...
It only took a moment until I realized that I just referred to one of the three rolling options when we have group loot within party in the game, when an item is being picked up from a dead mob (or a bag) there's a window popping up with the item in question, with three options to chose from, to roll "Need", "Greed" or "Pass" the item. I never told myself that I would "pass on toasts this morning", or perhaps I did but due to the addiction to the game during that time I think that I just thought about it as a reflex.
When I see threads in various discussion forums with the title "You play too much of [insert game name here] when...", I then immediately think "...when you think about either rolling Need or Pass on your breakfast" and laughing at myself.