I have always turned all my lights off when leaving my house, but recently I've realized how many of my friends don't! They do not even consider it, there lights just stay on all the time. I even had a friend who was leaving the lights on in her bathroom all the time, even at night, she would just shut her bathroom door. I've become the light police, and I think I have positively influenced at least a dozen friends to be more aware of their light usage and turning off unnecessary lighting when it isn't being used.