Some things go so far back in the dimly lit theater of the self it is hard to know whether they are early memories or recurrent dreams. One that is fundamental to me, though, is of lying on my back and looking up at a ceiling light fixture. I don't remember it as on or off, just up there. I can't reach it.
When as an adult I spoke to my mother about this image or memory, she told me my first word was "Light." Who knows how I pronounced the word--I must have pointed to it when she turned it on or off, carrying me into or out of the room. Mystery of adult power, mystery of electricity.
It made sense that this was an early memory when my son was a year old. We had a ceiling fan/light whose switch was on a chain, and he began to notice, when I was carrying him, how I switched it on/off. By age one, my picking him up so he could switch it on/off was a game we played, both of us making faces at each pull--light, dark, light, dark.
There are a even few photographs of this game from his first birthday party. Our faces are exactly the same comic mask.
A couple of books that may be may good for further musings on these things are Gaston Bachelard's "The Poetics of Space" (La Poetique de L'espace, on the intersections of memory and personal spaces) and Marc Auge's "Oblivion" ( on the interdependency of memory and forgetting, commemoration and public erasure, etc.).