when you go into the pub and ask for a pint of mead
When you've replaced the map of your state in your car to a map of Tamriel.
Mine's the opposite: Waking up to a detailed walkthrough in Skyrim makes me go "Omg..even in my sleep I'm in Skyrim" ahahaha..then I know, and I admit, i'm hooked!When you wake up and realise you didn't dream of Skyrim the night before (and you go "WHY didn't I dream of Skyrim last night?").