As an only child, whose parents divorced after a scant few years of marriage, I spent an extraordinate amount of time at home alone, playing by myself. No, I didn't say playing with myself, sicko.
So, around the age of 4, my mom became concerned as it seemed I developed an unnatural fixation with the attached mirror on my bureau drawers. She told me that she would stroll past my room, and was startled to hear me engaged in long, drawn out conversations while staring blankly into the glass. At first, she just blew it off, but then she noticed that I stayed awake late into the night talking to some unseen girl named "Rebecca." Things progressed over time to the point where I'd squander hours just conversing with my mirror. Worried, my mom started listening in, and told me that I spoke and laughed with "Rebecca" as though she were a real person.
Beyond freaked, my mom tried to lessen the time spent in my quarters. A couple years went by, and assuming that a change of locale would halt my behavior, we moved. It didn't change anything, and my mother finally decided to throw out the mirror with the curbside trash the night she walked past my room, and heard another voice speaking back to me.