As a child, you accidentally fell asleep on the couch one night while watching the Discovery Channel; however, the thing that believes it is you (which you know as your body) stayed awake for several hours thereafter. During that time, it learned everything there was to know about chameleons from a National Geographic special. Just before you regained consciousness, a stray curl of your hair snapped a horsefly from the wall, beginning a long and terrible process of transformation.
After that curious evening, your body found that it was able to camouflage itself as you perfectly. It even assumed complete control of your mind several times, and you never suspected a thing. As a teenager, however, you began to feel a presence within your skull, a sense of something phantom where your brain ought to be. You tried to ignore it, but the subsequent migraines demanded your complete attention.
Much to the surprise of that local radiologist you visited, an MRI revealed a large accumulation of dead insects jammed between the lobes of your brain. They speculated that somehow, these foreign bodies had passed through your skull’s sagittal and coronal sutures, yet could not explain how they breached your skin, having found no evidence of trauma or lesions.
You were, of course, promptly referred to an area surgeon for further investigation; however, it came to pass that “you” never showed up for your appointment.