When your teacher asks how Greece and Rome are linked, and you say they didn't have LOZ back then. (i did this 'cuz I'm a smart alack, and known for it)
You know you are addicted to it when you start humming various music from the game.
You know you are addicted to it when you play it steady for six months without playing another game,which i did.
When you play it through through the night without sleeping for a week you know your addicted to it.
Which is something else ive done many times.