In the four months since a mass shooting at David Hogg’s high school rekindled the gun debate in the United States, the sharp-tongued recent high-school graduate has become a leading voice of the student-led Never Again movement — and a lightning rod for contempt from opponents on the right.

That wasn’t an accident, he said.

In a new mini-memoir written by Hogg and his 15-year-old sister, Lauren, a sophomore at Marjory Stoneman Douglas High School, Hogg writes he’s been “difficult” since he was a kid. He explains how his struggle with a reading disorder and being treated like he was “defective” turned him into an activist eager for self-assurance.

The 163-page book chronicles the Hogg siblings’ childhood growing up in California as the kids of a gun-toting FBI agent father and an elementary school teacher mom and how the threat of mass shootings followed them as they uprooted and moved to Parkland, Fla.

Hogg said profits from book sales will go to “taxes and charity,” including to the advocacy group Change the Ref, which was started by Manuel Oliver, the father of slain Stoneman Douglas student Joaquin Oliver.

Lauren and David take turns writing about the fear of almost losing their father in the 2013 airport shooting in Los Angeles (he was stationed at the airport during the shooting, but was not involved directly), the trauma of living through the Feb. 14 school shooting in Parkland and how they became involved in the Never Again movement. The memoir ends with a 10-point (11, if you count voting) plan to curb gun violence and a tribute to victims of school shootings dating back to Columbine.

The plan includes banning “assault weapons,” funding gun violence research and starting universal background checks.

The book also attempts to explain how a small group of well-educated and hard-headed teenagers, some of whom were not friends before, banded together to demand change. With their debate skills, social media fluency and a “Let’s see who I can piss off” attitude, the students came to redefine the conversation around guns. They also raised millions of dollars for their cause and embarked on a voter registration tour ahead of the midterm elections.

Despite the achievements Parkland activists helped secure — like the passage of a sweeping school safety and guns bill in the GOP-controlled Florida Legislature and the March for Our Lives demonstrations — Hogg stresses toward the end of the book that his team cannot let entropy, or the gradual decline into disorder, doom them.

“But just like we learned in class, when progress starts, entropy rears its ugly head,” he writes.