Juan Diaz, a professional house flipper, takes $450,000 properties in West Oakland and transforms them into $1.5 million-plus homes.

It’s a good living. He drives nice cars, lives in a million-dollar home in San Carlos and pays $60,000 a year in private school tuition for his three children.

But something’s nagging him. He wonders: Is he a “gentrifier”? Yes, there’s that repulsive word: gentrifier.

Let’s consider Diaz’s walk of life.

We’re riding in his Mercedes cargo van on the way to Jingletown, a low-income East Oakland neighborhood of trucking warehouses and multifamily homes off International Boulevard.

It’s where he grew up.

Diaz, 42, is a first-generation Mexican American who dropped out of high school and was once in a gang. The young Diaz could’ve been the current president’s poster boy for everything he insists is wrong with this country right now.

As a kid, Diaz and his friends would go to the Del Monte cannery and swipe peaches off delivery trucks so they could sell them door-to-door in Jingletown. Back then, Diaz lived on East Ninth Street in a two-level home.

During the summer, the neighborhood kids ate free lunches of bologna and cheese sandwiches down the block at Mary Help of Christians Church. The field next to the church was their baseball field.

La Barca Market at 27th Avenue and East Ninth Street was where they bought candy from the peach sales. The intersection was also the weekend boxing ring for bouts between kids from the neighborhood. No helmets allowed.

“Nah, man, this is the hood,” Diaz says, laughing, as he steers through Jingletown. “You were lucky you had some gloves.”

Back then, the neighbors were family, and Diaz still has family in the neighborhood.

“Pretty much every house has some meaning to me, because I’ve been in every single one,” he says, before putting the van into park.

His uncle Domingo, who lives in Diaz’s former family home, is on the sidewalk smoking a cigarette.

“What’s up, señor?” Diaz says.

“Juaniño,” Domingo happily responds.

Diaz’s parents have a house in Fairfield, but they’re in Mexico for the winter. Every year they return to El Palomar, a speck of dust in Central Mexico. There’s no gas station or bank, and stores are run out of kitchens and living rooms. Gas is stored in Tequila bottles. Many residents from El Palomar resettled in East Oakland.

We take International Boulevard to East 41st Street in the Fruitvale neighborhood. His family moved here when Diaz started fighting in the streets without gloves. He was kicked out of Calvin Simmons Middle School and Fremont High School after brawls.

Behind the high school, he points to a room over a garage. When he and his friends cut high school, they’d have parties up there. By then he was in a gang. Where were the adults?

“Our parents were always working,” he says. “Always working.”

After a friend was shot and killed in the driveway of a house on Lyon Street, Diaz decided to focus on entrepreneurship.

As a kid he sold bubble gum out of his backpack at school. As a teen, he started a carpet-cleaning business. As a young adult, he restored cars, specializing in the Ford Taurus. He’d advertise in Auto Trader or park the cars at flea markets. He was introduced to house flipping by an uncle and his brother.

When we drive past Jefferson Elementary School on 40th Avenue, Diaz pauses to watch the kids playing at recess. He knows he has what others only dream of — a life outside of the neighborhood.

He worked hard to get there — still does, rising daily at 2:30 a.m. for work.

“It’s so different to get the picture when you can’t see it,” he says. “You don’t have that mentor painting a picture of what opportunity is out there.”

A white woman walking a dog crosses the street.

“There were no white people living here when I did,” Diaz says. “Absolutely not.”

For our ride, Diaz picked me up in Berkeley in front of a white Victorian he bought for $1 million a year ago. He’s putting $500,000 into the renovations, and he wants $2.2 million for it. It’s not a typical profit margin, but he’s preparing for what he believes is coming: a slump in the housing market.

So, yes, Diaz is a “gentrifier.” He’s also a success story from East Oakland, a neighborhood where failure drifts freely like trash in the street.

“I’m more for bringing up property value than keeping the neighborhood dirty and poor,” he says. “It saddens me that some people may not have the ability to remain here. I perceive it as more of a benefit toward Oakland, because what I grew up dealing with was nothing but crime and craziness.”

We stop for lunch at 4 Caminos Restaurant on San Leandro Street. Diaz still knows Oakland but, admittedly, it can feel like a different world compared with San Carlos.

He has worked hard, but he was told his son doesn’t “like his father because he works too much.”

“And that just hurt me,” Diaz says, balling up the napkin in his right hand. “I’ve got to change that.”

Gentrification takes a toll on everyone.

San Francisco Chronicle columnist Otis R. Taylor Jr. appears Monday, Wednesday and Friday. Email: otaylor@sfchronicle.com Twitter: @otisrtaylorjr