Donald Trump's yearbook photo at the New York Military Academy. Classmates.com Since announcing his presidential campaign in mid-June, real-estate mogul Donald Trump has mentioned his 1987 best-selling book "The Art of the Deal" in nearly every speech and media appearance he's had.

The Republican front-runner likes to say that the secrets to his success lie in the business memoir he cowrote with journalist Tony Schwartz.

In one of the book's early chapters, Trump, now 69 years old, explores several pivotal moments in his childhood that he considers showed signs of the man he'd become. We've summarized them below.

The time he punched his teacher in the face

Trump writes that he was aggressive and assertive from a young age.

"In the second grade I actually gave a teacher a black eye — I punched my music teacher because I didn't think he knew anything about music and I almost got expelled," Trump says. "I'm not proud of that, but it's clear evidence that even early on I had a tendency to stand up and make my opinions known in a very forceful way. The difference now is that I use my brain instead of my fists."

When he stole his brother's blocks to create a 'beautiful building'

Trump writes that his younger brother Robert often tells people a story of when they were kids that he thinks is indicative of his brother's destiny for being a ruthless real-estate developer.

They were playing with toy blocks when Trump was inspired to create a tall building, which would require some of his brother's blocks. Robert let him borrow them.

"I ended up using all of my blocks, and then all of his, and when I was done, I'd created a beautiful building," Trump writes. "I liked it so much that I glued the whole thing together. And that was the end of Robert's blocks."

Trump says that he didn't do this to upset his brother, but more because the opportunity presented itself. He says that as an adolescent, "for some reason I liked to stir things up, and I liked to test people."

Trump's part-autobiography, part-business-advice book was first published in 1987. Amazon

Seeing his father crush his competitors

Trump depicts his father, Fred, as a stern, aggressive, and practical man — traits that also came naturally to him. Fred was a developer in Queens who focused primarily on low-income housing.

"It was always amusing to watch a certain scenario repeat itself," he writes. "My father would start a building in, say, Flatbush [Brooklyn], at the same time that two competitors began putting up their own buildings nearby. Invariably, my father would finish his building three or four months before his competitors did.

"His building would always be a little better-looking than the other two, with a nicer, more spacious lobby and larger rooms in the apartments themselves. He'd rent them out quickly, at a time when it wasn't so easy to rent. Eventually, one or both of his competitors would go bankrupt before they'd finish their buildings, and my father would step in and buy them out."

Learning how to get along with a strict military-academy teacher

Trump's father sent him to the New York Military Academy to straighten him out and keep him out of the trouble he liked to get into as a boy. He joined when he was 13 and stayed from eighth grade to the end of high school, graduating as captain of cadets.

In retrospect, he is grateful for his time at the academy, where he says he learned how to channel his "aggression into achievement."

A particular teacher, Theodore Dobias, who was also his baseball coach, sticks out to Trump. Dobias served in the Army in World War II and didn't take disrespect from his students. Back talk would get you a hard smack, Trump says, and many of the students who didn't feel his wrath often shrunk in his presence.

Trump, though, says he learned how to get along great with Dobias. "What I did, basically, was to convey that I respected his authority but that he didn't intimidate me."

Realizing that academic pedigree doesn't indicate competency

Trump writes that because his father couldn't afford college, he held collegiate degrees in high regard. But once Trump got to the University of Pennsylvania's Wharton school as an undergraduate, he found his dad's college views to be idealistic.

"It didn't take me long to realize that there was nothing particularly awesome or exceptional about my classmates, and that I could compete with them just fine," he writes. He adds that he's glad he attended because society respects a degree from an elite school, but that it's far from a guarantee of future success.

Watching the coronation of Queen Elizabeth with his mom

When Trump was 6 years old in 1953, he saw his mother, a Scottish-immigrant housewife, enraptured by the pomp and circumstance of the coronation of Queen Elizabeth II. His father hated the royal family and was annoyed by the way his wife gushed over them, but Trump could identify with his mother's feelings.

"Looking back, I realize now that I got some of my sense of showmanship from my mother," he writes. "She always had a flair for the dramatic and the grand. She was a very traditional housewife, but she also had a sense of the world beyond her."