Another thing to think about is that enemies are just that: enemies. It is not a brave thing to fight your enemies. It is, in fact, a normal thing, and everybody does it. You're hard-wired to do it. It is harder to not fight your enemies than to fight them (that's why nonviolence is often so difficult to achieve).
A much harder, braver thing to do is to fight yourself. This time, there is no clear opposition, and the enemy comes from within, where there is no clear distinction between "you" and "it". The outside world will not know if you have succeeded or failed, so it becomes more difficult to motivate yourself. That's why it's always a good idea to tell people around you when you're trying to lose weight, for example, because then other people know you're trying to achieve something, and it makes it easier to stay motivated.
