Exactly. You never know what you're walking into. Life isn't a videogame where you know beforehand whether it's going to be a fistfight or a knifefight or a gunfight.
There are some people in the world that look like accountants or software engineers but they can kill you in a second and eat a pizza 5 minutes later.
I'm not one those people that goes looking for trouble or conflict. I don't start fights. I have never started a fight in my entire life, not even when I was a child. I don't need that headache in my life. But neither do I have any qualms about dropping the hammer on someone.
If a stranger attacks me for whatever reason I don't see it as a "fight", I see it as "combat". Which means I'm looking to end it as soon as possible. If that means some idiot is going to end up with a
linoleum cutter sticking out of his neck, so be it.