Let me tell you something about being a hero: It’s really a lot of fun. You walk around feeling great all the time. You have this terrific sense of purpose. You feel like John Travolta at the beginning of Saturday Night Fever, only minus the can of paint. Once, when I spotted two ninth graders having an argument outside the cafeteria, I walked up to them and very calmly told them that this was no way to settle their differences. “Are you the guy who won the wrestling match against Little Falls?” one of them asked. I told him, somewhat sheepishly,…