The surprise commencement speaker at the Florida high school where a gunman killed 17 people in February was Jimmy Fallon, who said he wanted to thank the students personally for their courage and bravery. “Most commencement speakers get up and talk in future tense: `You will succeed. You will make us proud, you will change the world,’ the “Tonight Show” host said. “But I’m not going to say that, because you’re not the future. You’re the present. … You are succeeding, you are making us proud.” Fallon joked about his own less-than-stellar high school performance — it took having to...