I hear voices sometimes.
I'm not insane. After all, the clinical definition for most mental disorders requires that they cause the sufferer distress, or impede the performance of his daily life. Yet I am not distressed, nor are my work or studies impeded. So, by definition, I'm not insane.
Nearly a century and a half ago, an American psychologist named Julian Jaynes proposed that humans have learned consciousness, that our minds were once bicameral. That is to say, though the left and right hemispheres of our brains are connected via the corpus callosum, they once operated separately, not together. To use an analogy, human brains once worked like two different computers connected together, able to share information but still distinct. Now, human brains work like one of those ancient dual-core computer processors, where the two chips operate as one. Integrated in a single Me. But in the old way, when the hemispheres communicated, the consciousness seated in one half of the brain perceived the information sent from the other half as the voice of an outsider, a god or spirit telling them what to do.
Even if the brain hemispheres are severed from each other, through a procedure called a commissurotomy, tests can be done to demonstrate that there is a consciousness present in each half, one independent of the other. You become, literally, two people in one body, though unable to communicate with one another. It's like taking that dual-core processor and snapping it apart, and somehow making two usable single-core processors out of them.
During my training, they performed several brain surgeries upon me, to study the nature of my gift firsthand as it grew, and to see how certain alterations of the brain reflected in alterations of the powers. Of course, I was never awake during these procedures. I never knew what they did, not precisely, but I think at one point they must have damaged my corpus callosum.
Not severed it. I've put myself through the various tests given to commissurotomy patients and found that I don't have the same responses. My brain is still functionally integrated. But I think it's not fully so.
So, I hear voices sometimes. Always when I use any of my powers. It's like a voice speaks out, telling me to do something that nobody else can do – read a person's thoughts, move an object with my mind – and it just happens without any conscious thought on my part. The voices are irresistible, and to hear them is to obey them. I couldn't actually describe to you the mechanism by which I employ my powers, they just happen.
So I'm not insane. If there is anything I am certain of, it is that. A little damaged, perhaps, but not insane.