At first it was barely noticeable, just a blip on my otherwise peaceful cognitive radar. But over time it would get stronger. The quickest way to relieve the pressure was to do something undeniably wrong, something I knew would absolutely make anyone else feel one of the emotions I couldn't. So that's what I did. As a child, I didn't realise there were other options. I didn't know anything about emotion or psychology. I didn't understand that the human brain has evolved to function empathetically, or that the stress of living without natural access to feeling is believed to be one of the causes of compulsive acts of violence and destructive behaviour.