Thomas Melindi was tested on the battlefields of Iraq and Afghanistan as a sergeant in the U.S. Marine Corps. Then he was tested in the classrooms of Orange Coast College.

On Thursday, as the student speaker at the college's graduation ceremony, Melindi, a Brooklyn, N.Y., native, playfully compared the two experiences, saying each was equally stressful.

But one thing is now certain: His next step in life is going to be just as calculated and concise as it was in the classroom and on the battlefield. That's because life after community college, he said, is more "a marathon than a sprint."

And if there's anything he's taken from his experience overseas in the Middle East, it's that he'll never take America for granted.

"The time I spent there shed light on how truly blessed I am to be an American," said Melindi, 25, who next will attend UC Irvine to major in business administration.

He was just one of more than 2,000 students who received their associate's degrees and career certificates as thousands of proud parents and friends filled into the outdoor Pacific Amphitheatre to watch the students, dressed in caps and gowns, receive their diplomas.

Next up for hundreds of students is either the real world or onward toward a bachelor's degree at a four-year university, whether from UC Berkeley, UCLA or Stanford, in state or out of state.

It was the 62nd annual graduation ceremony, and although he did not attend OCC, astronomy professor Nicholas Contopoulos said not a day goes by on the job that he doesn't enjoy walking to class and talking with the students, encouraging them to question everything and leave no stone unturned.

Quoting the great boxer Muhammad Ali, he said, "Don't count the days; count the days that count."

"Students," he added, "make your days count."

He went on to offer a few astronomical factoids: One, there are something like 350 other planetary systems outside our solar system; There's even one planet, in fact, that's filled with nothing but water; on another, if you were to visit it, you'd weigh 30 pounds lighter than what you are on Earth.

But just as Melindi loves America, Contopoulos extolled the virtues of Earth.

"We do not inherit the Earth from our ancestors," he said. "We borrow it from our children. The future is out there. Make it an exciting journey."

Jeff Hobbs, spokesman for the community college, said in an earlier interview that a quarter of the some 2,000 graduates received career certificates — that is, they are now experienced enough to go out and get a job, whether it's serving as a radiologist in the healthcare industry or becoming an emergency medical technician.

That's what the community college is all about, he said. It's about planning for the future, something hundreds of thousands of people are doing across the nation as the result of a high unemployment rate and a need for retraining for new jobs.

"But you've got to sign up early, in some cases, and get a jump on things" Hobbs said. "If you don't, there are waiting lists. That's how high the demand is for a community college education these days."

Also honored at the ceremony was Katrina Foley, a Costa Mesa City Council member, who was selected as the 2010 Citizen of the Year by the college. A total 1,376 students received Associate in Arts degrees, while 516 earned Associate in Science degrees. Certificates of completion were presented to 511 students.