"Think about your surroundings. Night time? Darkness. Day time? Distractions. You want to keep things quiet, invisible, or easily confused while doing everything in your power to do one thing and one thing only: get away safely." He met Draco's eyes, quite serious. "I'm serious about that. You might want to fight, you might want to hurt them, show them a lesson. Don't. You need to get away with your friend as quickly as possible or you risk him getting hurt, yourself getting hurt, or the situation getting out of control. It isn't glorious, to run, but it's better than what could happen."