With a year or less to go before the next federal election, scheduled for Oct. 19, 2015, Liberal Leader Justin Trudeau has published a memoir that's widely seen as his attempt to define himself before his political opponents do it for him.

Here are 7 revelations included in Common Ground:

1. His privileged upbringing

While his upbringing was one of privilege, it was also one shaped by the breakup of his parents and his mother's struggle with bipolar disorder.

Trudeau reveals many happy memories of his years growing up at 24 Sussex such as the secret code names the RCMP security detail gave his family, or the time he caught a glimpse of Diana, Princess of Wales.

"I was 11 years old and playing on the driveway of 24 Sussex with my friend Jeff Gillin. A car pulled up, the door opened, and an elegant young woman stepped out carrying a gym bag: it was Diana, Princess of Wales. She and Prince Charles were touring Canada at the time and I had been told she was discreetly coming over to swim some laps in the pool …"

"Jeff, his eyes as large as saucers exclaimed, 'Oh my God! That was incredible!'"

2. The collapse of his parents' marriage

Trudeau concedes the "sad times" are mainly connected to his parents' marriage and his mom's deteriorating mental health. Trudeau reveals he hesitated discussing his parents' divorce in the book, but in the end decided he had "no choice."

"I remember the bad times as a succession of painful emotional snapshots: Me walking into the library at 24 Sussex, seeing my mother in tears and hearing her talk about leaving while my father stood facing her, stern and ashen."

3. Michel's 'prescient' comments

Trudeau writes about the "spasm of guilt" he felt upon learning of his brother Michel's death in an avalanche while skiing in B.C., where Justin Trudeau was living and teaching at the time. He reveals the emotional toll it took on his father, who "was never the same man," and his mother, who "endured horrific debilitating grief."

He also reveals what Michel had told him years earlier.

"A few years before his death, Michel had been idly watching a TV documentary about burial rites in Asia when he stated, matter-of-factly, 'When it's my turn, just leave me down at the mountain where I lie.'

"His comments proved to be prescient: divers would never find his body, and he is there to this day."

4. Pierre's secret

Pierre kept his prostate cancer secret from his eldest son. Trudeau, who was teaching in B.C. in the spring of 2000, received a call from his brother, Sacha, who told him their dad was dying. Trudeau knew his dad had Parkinson's, but what he didn't know is that Papa had kept him in the dark about his prostate cancer, which was then in its terminal phase. He died by the end of September.

"'What the hell?' I almost shouted through the telephone. 'Why didn't you tell me?' Sacha explained that it had been Dad's orders to keep me in the dark. My father knew I would drop everything I was doing in Vancouver and return to Montreal the moment I heard about his condition.

"I knew my father had been trying to be considerate, but I was angry anyway."

5. How Margaret struck a blow against sexism in hospitals

Justin Trudeau reveals that his mother, Margaret, is responsible for hospitals allowing men into the delivery room to be with their wives when they give birth.

Liberal Leadership 20130414

Justin Trudeau, seen with his mother Margaret after he won the Federal Liberal leadership in April 2013, talks frankly about the dissolution of his parents' marriage and his mother's bipolar diagnosis. (Sean Kilpatrick/The Canadian Press)

"In 1971, the Ottawa Civic Hospital still excluded husbands from accompanying their wives in the delivery room. My mother was furious … If her husband couldn't be at her side in the hospital when she gave birth, she would have the baby — that was me — at 24 Sussex. When word of my mother's protest reached the hospital's board of directors, they promptly abolished the old-fashioned restriction, followed by other hospitals in Ottawa and eventually across the country.

"And I like to think that, along with my father, I helped my mother strike a blow against old-school patriarchal thinking."

6. Would Pierre agree with Justin's abortion stance?

Trudeau has come under fire for announcing that under his leadership, Liberal MPs have to support the party's pro-choice position. He reveals that his dad, who was a devout Catholic, would have approved of his position because of the importance he placed on the Charter of Rights and Freedoms.

"The Charter was his way of ensuring that it would be impossible for any group of Canadians to use the government to unduly restrict basic freedoms for any other group of Canadians. His core value was classically liberal in this sense. It is a value I share, and believe in equally deeply.

"Because of the Charter, women have gained the right to control their reproductive health.

"In the spring of 2014, I would announce a firm stance in favour of a woman's right to choose. It was a big change for some of my parliamentary colleagues.

"My idea of freedom is that we should protect the rights of people to believe what their conscience dictates, but fight equally hard to protect people from having the beliefs of others imposed upon them.

"When MPs vote in Parliament, they are not just expressing an opinion; they are expressing a will to have all other Canadians bound by their opinion, under law.

"I am confident that my father, were he around today, would agree."

7. What he learned on the PM's plane

Before Trudeau decided to run for the leadership of the party, he gathered a trusted group of friends for a three-day retreat around a campfire in Mont Tremblant, Que., where they debated whether the party was worth saving or whether it should merge with the NDP. Trudeau reveals that coming to big decisions in this fashion is one of the lessons he learned from travelling with his dad on international trips.

"The most valuable part of these trips with my father was the chance to watch how he made decisions. He was always asking questions and challenging people around him about their opinions.

"Any decision made by my father was the result of a process that had involved many voices, and which sometimes had taken weeks or months.

"The decision-making model I learned during those 707 flights has come to inform my own leadership style."