I just had a thought.
For a moment, consider your "light switch memory". How many rooms can you walk into and reach for the light switch without the slightest thought, apart from, "Hey, it's dark in here!"?
A lot of rooms have switches that are further inside or closer to the door, or high up or low down. Wherever it is, our hands find it fairly quickly, even in a room we haven't visited in a while (but had frequently turned the light on before).
For example, in my first apartment in college, the bathroom light was on the outside of the tiny room with the toilet and shower. It became habit to seek it out before going in, and I pretty much conditioned myself to do it in that particular room of that particular house. I'd bet that I could go back there and my hand would automatically drift back to that switch with barely a thought.
I wonder what would happen if you moved some light switches around, like from the inside of a room to the outside, or to the opposite side of a doorway. You could really mess people up doing that. At least, until they figured it out and reteach themselves.
Then you could switch it back. :)