>Yeah but I always turn off lights as I leave a room
Do you plan to live alone forever? 'cause roommates, spouses, and especially children tend to make turning the lights off as you leave the room quite futile.
Almost everyone in my life knows to turn the lights off when they leave the room too. It was also drilled into us as kids to not waste energy. I've drilled it into my SO. It's really not that difficult of a habit, switches are by the door.
Can't control roomies but that's about it.