Businessman and Republican presidential candidate Donald Trump told a biographer that his time at the New York Military Academy gave him "more training militarily than a lot of the guys that go into the military," according to the New York Times.

Trump reflected on his education and its resemblance to military school in interviews with Michael D'Antonio, a former Newsday reporter, who is publishing a biography called "Never Enough: Donald Trump and the Pursuit of Success" on Sept. 22. The Times received an advance copy of the book from the publisher, St. Martin's Press.

Trump transferred to the New York Military Academy in eighth grade after attending Kew-Forest, a prep school in Queens, where he was apparently a rowdy and rebellious student. In one story contained in the biography, he recalls giving a teacher there a black eye "because I didn't think he knew anything about music."

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At New York Military Academy, students wore uniforms, participated in march drills and adhered to a strict hierarchy. The culture, he told the biographer, meant he "always felt that I was in the military."

Trump did not serve in Vietnam because of medical deferments for bone spurs in his heels (which he showed D'Antonio during their interviews) and later, a high draft number: 356 out of 366.

"My number was so incredible and it was a very high draft number. Anyway so I never had to do that, but I felt that I was in the military in the true sense because I dealt with those people," he told Mr. D'Antonio.

The businessman's military record has already come under scrutiny in the 2016 campaign because of his criticism of Arizona Sen. John McCain's war record in July.

"He's not a war hero," Trump said at the Iowa Family Leadership Summit when moderator Frank Luntz brought up McCain, who spent more than five years as a prisoner of war in Vietnam.

Immediately modifying his original remarks, Trump added, "He's a war hero 'cause he was captured. I like people that weren't captured, OK?"