"When you think of commencement speakers, you think of people who are inspirational, people who are eloquent, people who've changed the world," he said. "When you think of high school students, you think of people who are immature, slightly awkward, still learning to be an adult."
In the ceremony's venue, the BB&T Center, home to the Florida Panthers hockey team, Fallon then delivered the graduating seniors some "real-world advice."
"When something feels hard, remember that it gets better. Choose to move forward. Don't let anything stop you," he told the graduates, who wore sashes that read "MSD Strong."
The families of the four seniors who had died in the shooting — Nicholas Dworet, Joaquin Oliver, Meadow Pollack, Carmen Schentrup — accepted diplomas on their behalf.
He mentioned having met some of the students at the "March for Our Lives" protest in Washington, D.C., earlier this year: "It was an amazing day."
"Thank you for your courage and your bravery," he said, "and for giving amazing speeches I could never possibly live up to."
He says he and his wife brought his two young daughters to Sunday's event "because we wanted them to see what hope and light looks like."
The comedian poked fun at what, at first, he saw as a personal setback for his younger self, who he said "wasn't dumb" but "just had other strengths." Obligated to go to summer school, happily, he said, it turned out "I met 15 versions of myself. Everyone was funny — and slightly dumb. I loved summer school!"
In other words, he said, "Some things that seem like setbacks can take our lives in a totally new direction — they change us in ways we don't expect. And they make us better, and stronger."
"You guys have already proven that to everyone," he said. "You took something horrific, and instead of letting it stop you, you started a movement."
"The whole world has heard your voice. And that was you making a choice," he said. "That was you choosing hope over fear."
You can listen to Fallon's full commencement speech below:
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