Self-defense doesn't just mean protecting yourself from getting punched by the other guys; self-defense means avoiding the fight at all costs because of the possible variables that could come into the fight that you could have never predicted could be the ones, ultimately, to defeat you, right? You don't normally think about that. You think of losing to the opponent. No, you lose to the circumstance, you lose to the environment, you lose to the bystander who kicks you in the head because it's his friend that you're fighting and you didn't see them.