A childhood belief about mirrors

When I was a kid, in the bathrooms, there was the big wall mirror and then a smaller one on the door of the medicine cabinet, so they would face each other when the cabinet was open. I was convinced that the "corridor" effect created by two mirrors facing each other closely was a sort of a dimensional portal (spent too much time reading big brother's Dungeons and Dragons books, maybe... and now they're mine, heh heh), and I had only to figure out how to "open" the big mirror so I could crawl through the corridor into a fantasy world where I could learn more magic and get myself a suit of armor and cool medieval weapons. I thought maybe writing the right thing in the mist from a shower would do it. I puzzled over this until I was a good nine years old...