"I've never accidentally stabbed anyone, but I have accidentally burned someone with a cigarette butt."
We spoke to a man who suffers from Body Integrity Identity Disorder, a rare condition that makes you feel like one of your limbs doesn't belong on your body.
Imagine waking up in the middle of the night and feeling a drill in your eye and feeling like somebody has pierced a hot metal rod through your neck and rammed it up into your brain. This is not a metaphor. This is what a cluster headache feels like.
PBA is a brain disorder that causes hysterical crying in happy people, and uncontrollable laughter in sad people. We interviewed one of the doctors leading the research into this strange and oddly damaging phenomenon.