>>/8955/
There is one thing: it isn't easy to kill someone, especially if you have no weapons. And even with knife it isn't easy as may look. People are sturdy creatures, and you can easily stop being in affect while being in fight, and everyone will live. Beating, for example. easily gets your anger off in few minutes.
Being good in classic hand-to-hand combat also requires training, that is why in Medieval times warrior class wasn't numerous, and there often was shortage of proper soldiers while general population was large. When guns appeared, everything changed. I think it is mostly technical thing.
>>/8957/
> Also I think (I hope) most of us don't have first hand experience on killing
I almost killed one person in self-defense situation when I was kid. Maybe he even died later, I don't know results. I clearly remember that I didn't care about severity of my actions when I did this and didn't had any moral block. I was very affected and didn't control myself (although I had no choice).