is dedicated to Michelle, 22-year-old Malia and 19-year-old Sasha Obama. In an Instagram post on Saturday, the father of two posted a sweet message about why his children are his priority—and why that will never change.

"The fact that my own father was largely absent from my childhood helped shape my ideas about the kind of father I intended to be," he wrote. "When Malia was born, I made a promise to myself that my kids would know me, that they'd grow up feeling my love keenly and consistently, knowing that I'd always put them first. While serving as President, I made sure to have dinner with Michelle, Sasha, and Malia every evening by 6:30. We'd eat some good meals and catch up on our days. That was one of the best parts of living above the store, as I sometimes called it. Seeing them grow up into the intelligent, strong, and compassionate young women they've become has been the greatest joy of my life. I'm reminded constantly that there's no place in the world I'd rather be than with Miche and our girls—and it's why I've dedicated my memoir to them."

In the past, Obama has been open about his father, who was not around during his childhood. In a Father's Day address in 2008—while he was on the campaign trail—he touched on the other parental influences he had in his life.

"I know what it means to have an absent father, although my circumstances weren't as tough as they are for many young people today," he said. "Even though my father left us when I was 2 years old, and I only knew him from the letters he wrote and the stories that my family told, I was luckier than most. I grew up in Hawaii, and had two wonderful grandparents from Kansas who poured everything they had into helping my mother raise my sister and me—who worked with her to teach us about love and respect and the obligations we have to one another."