A grandpa, a "grateful American" and a recipient of the military's highest honor shared life advice and reflections on the meaning of Veterans Day on Friday with 2,700 high school students.

During a patriotic assembly at Naperville North, Medal of Honor recipient and retired U.S. Marine Col. Harvey Barnum told students to make the most of the freedoms veterans fought to protect by aiming high in their own lives.

"Always set goals. Never say 'I can't.' Take the word 'failure' out of your vocabulary," he said.

The 77-year-old Connecticut native shared his "grandfatherly advice" before attending the Naperville Marines Ball Friday night to celebrate the Corps' 242nd birthday.

Naperville North social studies teacher Jeff Bedore, a Marine veteran himself, told students in a video they watched before the assembly that the Medal of Honor is reserved for "extraordinary courage under the most difficult conditions imaginable."

Barnum received it at age 25 for his service in Vietnam, where he risked his life to assume control of a unit after its commander was killed during a firefight. But he told the students battle is something everyone hopes to avoid, even those in the military.

"War is horrifying," he said, "not glorifying."

After receiving the recognition, Barnum said he returned for a second tour in Vietnam "because I was a professional Marine." He then served as Deputy Assistant Secretary of the Navy and briefly as Acting Assistant Secretary of the Navy.

He said he has attended inaugurations and met every president since John F. Kennedy and doors have been opened in his career because of the medal. But if it makes him a role model, it also carries a weight.

"This has been harder to wear," he said about the star-shaped medal on a blue ribbon around his neck, "than it has been to earn."

Naperville Marine veteran Lewis Breese, who arranged Barnum's visit, said the honored veteran's actions in Vietnam and beyond fit the truest definition of heroism.

"A hero," Breese said, "is someone who does the right thing at the right time, regardless of the consequences."

Barnum told the students he stood before them as a "grateful American," who appreciates freedoms of speech, press, assembly and the right to vote -- all of which veterans earned for the nation.

"Veterans have sacrificed so that Americans -- you and me and others -- could live in freedom," he said. "They have demonstrated to us that freedom -- freedom -- is the mightiest force on earth."

Since Barnum's time in Vietnam, he said members of the military have been fighting "isms," citing totalitarianism, communism, extremism and terrorism as some of the dangerous ideologies among them. Again he praised veterans as the nation's protectors.

"We live in a volatile, unstable world today -- that's why we have a military," Barnum said. "They're fighting away games so we never have a home game like we did on 9/11."