You know you're addicted to Orbiter when you are following a launch of a spacecraft in Orbiter in real-time.
From yesterday's chatbox, jedimaster1214 is apparently guilty for that.
... when your brain orders your arm to press "T" during a long wait, then immediately inhibits the move, understanding it will not work (happened a couple of times to me)...
...when you recommend Orbiter to everyone you meet
...when you have 5 different Orbiter installations on your computer.
...when you are in school, on the last class of the day, you look at your watch and start to think: "10, 9, 8, 7, 6, we have main engine start, 3, 2, 1, (the bell rings) and liftoff!".