I learned and taught self-defense for many years. Enough to say you can never know for sure about someone, I’ve seen some really unassuming people turn into beasts in the sparring ring, and seen some big, tough dudes not be able to take a light gut punch.

All that said, I would be shocked if someone like Zuckerberg could handle the swift, primal, animalistic speed and violence that comes with an actual fight. He lives out-of-touch with the world and doesn’t have to watch his back on the bus ride home or learn how to spot dangerous people ahead of him hanging out in a parking lot. Even if he’s really good at katas and sparring, it’s a far cry from actual fighting, and survival comes from as much mental preparation as it does physical.