PORTSMOUTH, New Hampshire (CNN) -- Sen. John McCain's visit Tuesday to Concord High School proved to be more than the average guest speaker appearance, with the Republican presidential candidate giving and getting a dose of the campaign's trademark "straight talk."

While campaigning Tuesday with her husband, Cindy McCain uses crutches after twisting her knee.

During the question-and-answer session, one student rose and asked a pointed question about McCain's age, 71: "If elected, you'd be older than Ronald Reagan, making you the oldest president. Do you ever worry that, like, you might die in office or get Alzheimer's or some other disease that might affect your judgment?"

The Arizona senator chuckled slightly as comments of "Oh my God" filled the room. In a self-deprecating reference to his memory, McCain said his children have joked about their father "hiding his own Easter eggs," but quickly added that he is a "24-7" worker and will out-campaign any of his rivals.

McCain ended the exchange in his quintessential style: "Thanks for the question, you little jerk. ... You're drafted."

Another student then asked McCain a question about what he would do for rights for "LGBTs" -- lesbian, gay, bisexual, and transgender people. McCain was confused by the question and acknowledged to the audience that he did not know what the initials meant.

Once the meaning was clarified, McCain told sophomore William Sleaster he is opposed to any form of discrimination, but he supports the military's "Don't Ask, Don't Tell" policy and he opposes same-sex marriage.

"I believe that the sanctity of marriage between man and woman is unique and should be preserved, and I understand the controversy that swirls around that issue, and that debate needs to be continued to be held, but I support that position," McCain said.

"You want to take away someone's rights because you believe it's wrong," Sleaster followed up.

"I don't put that interpretation on my position, but I understand yours," McCain responded, seeming to enjoy the back and forth.

"I came here looking to see a good leader. I don't," Sleaster said before leaving the microphone to some boos and gasps from the audience and an eventual scolding by a school administrator.

"Listen, I understand," McCain told the buzzing crowd. "I thank you. That's what America is all about, and I appreciate your views."

Asked later at a news conference, McCain said he had never heard the initials "LGBT" before, but knew the phrase.

Iraq dominated much of McCain's comments before the packed auditorium. He reiterated his support for U.S. strategy there, and played up his criticism of the way the war was handled until recently.

"I was the only one of the major Republican candidates who adamantly, vociferously opposed the [former Defense Secretary Donald] Rumsfeld strategy and fought hard for the strategy [of using more troops] that we're employing today," he told reporters. "The others thought it was fine. That's because they don't have the knowledge or background and experience that I do on issues of national security. That's a clear indication of it." E-mail to a friend

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