For the first time in 10 years, Sanford H. Calhoun High School Principal David Seinfeld didn’t deliver a speech at Sunday’s commencement. Instead, Seinfeld forfeited his slot in the program to a young man who, he said, is far more inspirational.

In order to graduate with his 350 classmates, Dean Brownworth, 18, of Merrick, had to overcome cancer. Brownworth was out of school for most of his junior year and the first four months of his senior year, undergoing surgery, radiation and chemotherapy to treat a cancerous tumor in his brain. He said he lost 25 pounds off his already slim frame and his hair fell out four times over, but he was able to return to school in early January and was back on the court, playing for Calhoun’s basketball team, shortly after.

“Life throws curve balls at all of us, and sometimes we are knocked down,” said Brownworth, who also played baseball for Calhoun. “But you have to get up, you have to find the strength to carry on, to continue the journey. You need to believe.”

Speaking from his experience, Brownworth told his classmates that when they do encounter unexpected obstacles, they should “stay positive, stay focused on their goals and stay close with family and friends.”

Sen. Chuck Schumer stepped up to the podium at the NYCB Theatre in Westbury after Brownworth. He spoke of tax incentives available to help families pay for college and shared some stories from his past -- from a failed romance to his first electoral victory. Then, hoisting his hand above his head, he told the 2013 graduates, “Figure out what your dream is… and go for it.”

Calhoun’s 2013 valedictorian, William Mansmann, 18, had a different challenge for his classmates, though. Rather than solely focusing on their individual goals, the Cornell University-bound Merrick resident told his fellow graduates they have a responsibility to work together to make the world a better place.

Calling his generation “underdogs,” Mansmann said, “There are a lot of negative expectations about our generation. People don’t seem to believe that we can accomplish what generations of the past have accomplished.”

He challenged his classmates to refuse to let those thoughts define them.

“Society can tell us what it expects us to do, but it is our decision to determine the fate of the generation,” he added. “If we continue to learn, and choose to do what is right, we can defy those expectations, alter those perceptions and uphold our responsibility to make this world a better place for the next generation.”