to continue what Erik said:
everyone does know how to fight. Most everyone knows how to make a fist and/or flail their arms around in a fashion that could hurt or injure someone (perhaps even themselves?) if needed, but few people have the courage and instinct to act on that if needed.
Nick, could you clarify this for me? I think that almost everyone, if not everyone, has the capability, willingness, courage and instinct to make you dead. You just have to give them proper motivation. Check the history books. Killing and violence have never been a difficult thing for humans.