Rob Lowe reveals his parenting secret and how it has paid off

Rob Lowe’s grown sons, Matthew and Johnny, love to mercifully troll their dad on Instagram.

But the three weren’t always buddies.

“Of course I wanted to be loved and liked by my kids, but I wasn’t their friend,” Lowe told TODAY Parents. “I was there to help them and guide them."

Lowe, 56, recalled how he and his wife, Sheryl Berkoff, used to keep bowls of candy in their home to teach the boys self-control.

“We’d have a vase of M&Ms in various rooms and they knew not to grab from it without asking,” Lowe explained. “They knew it belonged to mommy and daddy.”

Johnny and Matthew’s playmates understood the rules too when they came over.

"Sheryl and I had a reputation for the being the most strict of anyone’s parents,” Lowe said. “We valued intellectual curiosity and grades. Academic accountability was huge."

And it paid off: Matthew is a Duke University graduate and attorney, while Johnny, an actor, received his bachelor’s degree from Stanford University.

Though Lowe values openness and honesty, he was careful not to overshare details of his past, which includes a descent into alcoholism and drug abuse. (The “Parks and Recreation” alum marked 30 years of sobriety in May.)

“They knew everything about me from day one,” Lowe explained. “But there’s a whole area of things that’s none of their business. And the reason it’s none of their business is because it’s not going to help them. We're all entitled to our own history. We don’t have to be an open book for our kids.”

Lowe opened up to TODAY Parents while discussing his partnership with the online genealogy company Ancestry.

After learning more about his history, Lowe said he now understands why he is drawn to playing patriotic characters such as White House communications director Sam Seaborn on “The West Wing.

“My four-time grandfather fought for the Union in the Civil War,” he said. “My family is deeply involved in the fabric of this country. It’s in my genetic makeup.”